It was a pretty ordinary June day in 2015. I had no premonition of the extraordinary way in which my life would change. I was in my late thirties, and not doing much of anything. I had gained a BE/BSc. combined degree in Engineering and Science from the University of Melbourne and had been a reasonably successful freelance journalist, specialising in science reporting. I had decided to move from Melbourne back to my old town, Perth, chasing the sunshine and escaping from a relationship that had turned sour. In other words, I'd put work before my personal life and screwed up, once again.

Our Melbourne apartment had sold for a good price and, after paying off the loan, my share was just short of two hundred thousand, so I was considering taking it easy for a bit - not looking for work until I got bored. That's what made me decide to go back to Perth. I had a couple of assignments and commissions with publishers in the pipeline and I reasoned that I could do them just as easily from there.

The ageing Holden utility that I was driving over to Perth in was playing up a bit and, by the time I reached Southern Cross, on the fourth morning of my journey, it was overheating badly. I stopped at an auto service centre on the main street for help, but the man in there said it looked like a major problem that would need to be looked at in Perth. He suggested that I top up the radiator and carry some spare water. I decided to let the engine cool a bit before doing that, so I went to a cafe across the road for a cup of coffee. I grabbed a couple of old magazines from the rack and sat down with a coffee and a sausage roll.

I looked up and saw a tall, rather pallid looking man come in. I took a quick look at him and thought 'this bloke looks a bit odd - can't put my finger on it, but it's something about his clothes'. I felt sure that I had seen him before, at a previous stop at a filling station. Then I got onto my phone and started to look for apartments to rent. As I was giving my name to a real estate agent I glanced up and saw that he was sitting at my table and looking at me intently. I said "D'you want a magazine mate? They're not much cop, but it's better than sitting here twiddling your thumbs". The man replied, in an accent I couldn't pace, "Thanks, but no."

The clothing and the accent had mildly aroused my curiosity so I asked him if he was local, or a visitor here. The man said that he was a visitor, but drove through here often on his way to Perth. When I asked him where he was from, he was evasive, saying "Oh, a long way from here, a place you wouldn't know." and then he turned the conversation to me. We introduced ourselves and when I told him that I was a science journalist and was just moving to Perth, he nodded as though he already knew. He then started asking seemingly casual questions about my background, family ties, current situation and future plans - a bit of a 'third degree', I thought. He finally stopped asking questions sat there quietly, appearing to mull over what I had told him. After an awkward few minutes of silence, he surprised me by saying that his organization might be able to put some work my way. He then got up to go, handing me a card and telling me to call if I was interested in talking about a long-term assignment. I said thanks, put the card in my wallet, and sat there wondering 'what the hell was that all about?'

When I finally reached Perth, I had about an hour to spare before an appointment to see a rental apartment so I pulled over into an auto service centre along the Welshpool Road. The mechanic said he would put the ute up on the hoist and have a look, so I sat in the waiting room flicking through greasy boat and car mags and drinking shitty coffee from the machine. I started to think about the strange meeting at Southern Cross but it went from my mind when the manager came out and told me what was wrong with the car and just how much it was going to cost to fix it.

By the late afternoon I had already looked at four unsuitable apartments and this was the fifth rental property I had looked, at and it was pretty crappy - cheap construction, lots of minor damage, unkempt gardens and an indifferent real estate agent. I told her it was unsuitable and she just muttered something unintelligible, locked up the unit and drove off without another word. Not a good day. Car needs a couple of thousand spending on it, two hours wasted looking for somewhere to live and some weirdo propositioning me in a roadside cafe. Well, perhaps not exactly propositioning me - maybe offering me a job - but a bit strange all the same.

Sitting in the garden restaurant of my hotel that night, after a steak and chips and half way through a bottle of Shiraz, I was feeling pretty relaxed. My mind started to lazily drift through half-formed ideas for the next stage of my life. My main impetus for moving west, I realised, was to put a good distance between myself and my former squeeze. I was uncomfortable with the prospect of accidentally bumping into her in Melbourne. Little did I realise how much distance I would eventually put between us! My other reason for coming over to Perth was to do what I was doing right then - relaxing a bit and having time and space to consider my options. On the drive over from Melbourne I half imagined an idyllic barefoot and bearded beach-side existence, drinking cold beer and catching fish to cook on the barbie, but I soon discovered that there were very few places near the beach that I could afford to live in for very long. 'Anyway', I thought, 'I'm probably an incurable workaholic and I now realise that I'd go stir-crazy sitting around doing bugger all, so I'd better start getting some ideas together'. Just then some unacceptably loud tourists flopped down into chairs at the table behind me, so I decided to finish off my wine and go to bed to sleep on it.

The next afternoon I picked up my ute, which seemed to be running okay now. On an impulse, I decided to have a nostalgic look around the State before I found somewhere permanent to live. For the next week I drifted from place to place, sampling the wines and cheeses of Margaret River, seeing the forests of the South-West and taking a trip out to see the whales in the Southern Ocean, off the old southern whaling town of Albany. Then I headed east along the long southern coast road to see the magnificent beaches and the pink lake outside Esperance. From there I turned inland, going north to the Kalgoorlie gold fields.

Wearily sitting with a coldie in a Kalgoorlie pub, and attempting to recover my strength for the long drive back west through the wheat belt to Perth, I started to think about what I was going to do when I got there. As I saw it, I had basically three options. The first was to get back to some research and write stuff to offer to science publications. The second was to crank up some of my old contacts and see if I could score commissions to write articles for the popular science magazines. Or thirdly, I could do something completely different; postie, personal trainer, toilet cleaner or something! None of these really appealed to me. I wanted a break from the grind of churning out articles but he didn't fancy a low paid job working for some arsehole.

Then I thought about the tall skinny bloke who had given me his card at the auto repair shop last week. 'I might as well give him a ring when I get back' I thought. 'Might be something in it, something a bit different'.

When I got back, I sorted out a squat in a backpacker's, to save a few bucks. That turned out to be false economy as somebody pinched my wallet and cash from my room while I was having a shower. Fortunately, I'd put the strange fellow's card on the bedside table but, as I had to spend most of the next day with the police and sorting out replacement credit cards and a driver's licence, I didn't get around to contacting him. The following day I was so pissed off with recent events that I was determined to give him a ring to get my mind off my problems, and onto something else.

This was the first time I had really looked at the man's card. It was plain white, with printing on one side only, and it just had his name, Joseph Booth, with a cell phone number. Nothing else. Neither an address nor a company name. No clues as to who he represented, or what they did - nothing I could look up on the Web. If the job was Kosher, then presumably it would be something to do with science or journalism, but, a bit strange!

The call was answered immediately, and Booth's voice said "Mr Mortimer, how good of you to contact me". 'Wow,' I thought, 'how the hell did he do that? Must have got my cell phone number from somewhere and put it in his phone addresses - spying on me?' He then said "You are probably wondering how I knew your phone number, after such a brief meeting. Well, I have to confess that I have been doing a little research on you. I hope you don't mind".

Taken by surprise, I said "No-oo, that's okay" and added jokingly, "as long as you didn't uncover any of my dirty dark secrets". Booth replied with a query in his voice "No, we didn't Mr Mortimer, would you care to tell us what they are?" 'Oh shit,' I thought, 'I've blown this one already'. "No, no, Mr Booth, just joking", I said.

Booth grunted something unintelligible and went on to ask if I had considered his offer to discuss joining his organisation, on a special project. I said I would be happy to meet again and find out more about it. I agreed to meet the next morning - a Sunday - at Booths office.

Just as I shut my mobile phone down it rang again. It was my dad with some sad news.

He said he had just found out that old Harry had died peacefully in his sleep about a week ago. He had apparently been getting a bit frail but refused to leave his home, but a neighbour had been keeping an eye on him, for the family. He said that Harry's solicitors had contacted him and asked him to contact me because I was a beneficiary under his will. Dad had a copy of the will, which left his country property to me 'because he's my Godson and he loved the place so much when he was a little tacker'. This left me with a mixture of sadness, surprise and a feeling of guilt for not keeping in touch.

I phoned Booth back and asked if we could postpone our meeting. When I told him what had happened, he was most understanding, but didn't seem surprised. I had the strange feeling that he already knew about old Harry's death.

After the funeral dad and I had a long chat about the property and what to do with it. I told him that he could have it if he wanted, as Harry was his friend really. He thanked me, but said that Harry obviously wanted me to have it. "In any case," he said, "I'm still fully involved in my business and I couldn't spare the time to properly look after a rural property." Dad had partnered with a friend and started up a tech company a few years back - and it was growing rapidly.

He asked me what I was going to do with it. Move in or sell it. After a lot more talking it over, I decided to have a go at fixing it up, and live there for a while. When I originally learned of the bequest, my first thought had been to offer it to dad and, if he didn't want it, contact a real estate agent and put the property on the market. But, as old Harry was so content there and had probably left it to me in the expectation that I would keep it, I decided that I should hang on to it for a decent interval, at least. Besides, I had happy memories of the place.

I also had some unfinished business there. The strange events in the cave had stayed in my mind and I was determined to investigate further. I could never have imagined what an incredible story that investigation would eventually reveal.

It had been a hectic two months since moving in, but I'd just sent off the final drafts of some articles to my publisher, and I had finally got the house and land more or less the way I wanted it. Harry had kept it in pretty good condition but it had obviously suffered a bit of neglect in his last few months, as his health deteriorated. My mind wandered to the 'unfinished business' and I started to wonder where my old friend Huey was now. I had lost touch with him after we had both left Uni in 2000. I decided to try and track him down.

I did a web search first - no hits. Then I tried all the Australian White Pages - still no luck. Finally, I called an old mutual friend in Perth who told me that the last he heard was that Huey was in the UK doing research, or something, at a certain University that he named. A web search revealed that there was a Dr Hugh Mannix on the faculty. I remembered that Huey's last name was Mannix, so he had done his PhD, as he intended. It listed his doctoral speciality as relating to aspects of astronomy, astrophysics, and stellar structure. He always was a clever bugger, but I never dreamt that he'd get this far. It made me feel as though I hadn't achieved much in my life, so far, and I was a bit jealous.

The University site also gave his contact email address. Although I thought that there was not much point in looking for his help if he was over in the Old Dart, I decided to email him anyway, to say hello and tell him that I was back in Western Australia. So, I did.

Huey replied, saying it was great to hear from me and that he would look me up because he was coming to Perth, to see his mother, in a couple of week's time. I emailed back and told him that old Harry had died, left his place to me and that I was living there. I invited him to stay for a while. He got back to me straight away and appeared to be highly delighted to come and drink and 'talk shit' for a few days - he said he loved visiting his mum, but it was a bit of a 'duty visit', and it would be great to have a break from home cooking and mothering.

The morning I picked Huey up at Terminal 1 of Perth International Airport it was bright and sunny, and not too hot. To me, he looked a bit pale from lack of sunshine but he seemed fit, happy and healthy. Pretty much as I remembered him except that he was now taller and fairly solid. It was good to see him again and it brought back a lot of old memories of the times we had as kids. He said it was great to be back and that he was looking forward to a bit of leisure and sunshine, a visit to his mum, a bit of catching up with me and a bit of adventure too.

I took him over to see his mother, who lived in a suburb to the south of Perth city. He told her that he was going to spend a few days with me first, and come back to see her later. She protested a little, but seemed a quite relieved. She lived in a small, well-ordered house and I'm not sure she wanted a big fellow like Huey crashing around there for too long.

I mentioned the cave to him and said I had been thinking of having another look. Huey said he had done a bit of potholing in the Karst caverns in the Nullarbor, before leaving for England, and his mum still had his gear. He got it out of her shed and threw it in the ute, saying we might need it. We then drove up north to old Harry's place. I still thought of it as old Harry's, even though it was now mine.

When Huey had unloaded his gear into the house, we grabbed a couple of cold beers and I gave him a quick tour around the property. He said it was a lot like he remembered but that everything seemed a little smaller. He looked pleased to be there and I could see that the signs of work stress were beginning to fall away.

We threw a couple of steaks and a few prawns on the barbie that evening, downed a considerable quantity of ale and swapped stories about what we had been doing in the intervening years. Later, after a few more beers, we discussed and solved all the world's problems.

The next day I got out a box of Harry's old papers and pulled out the photos that we had taken down the cave twelve years before. We were both keen to go into the cave again and see if we could get a better look at the peculiar 'rock formation' that I'd photographed.

We decided to have quick look at the site straight away but when we got out there Huey said it all looked different now, supposing it was because we were smaller then. It was twenty-six years since had last been there and we couldn't find cave entrance at first, then I remembered it was up the top, almost directly above the old gnarled leaning tree at the bottom of the slope; perhaps a little to the left.

We climbed up and eventually found where entrance had been, but the rocks above had collapsed, all but blocking the way in. Whether it had been done by old Harry, or the rain and wind had eroded the rocks, we couldn't be sure. There was just one small hole left which was far too small for us to get through. Just about big enough for a rabbit. I could feel a cool breeze coming out.

We went to bottom of slope to have a think. We finally realised that it would be would be far too much work to unblock it by hand and we couldn't get any heavy equipment up that slope.

From memory I reckoned that the passage I'd discovered all those years ago would have run in a roughly westerly direction, if it continued straight through past the blockage. That would bring it out somewhere at the bottom of the slope where we were standing. However, we couldn't see anything at all; just scree and small limestone outcroppings. There was nothing that looked like another entry, not even a small one.

We were a bit despondent because our adventure seemed to be over as soon as it started. The 'buried treasure' had eluded us. Sprawled under the cooling shade of the windblown, leaning tree, we drank some water and said little. We were both wondering what to do next to amuse ourselves for a few days and concluded that the beach and a bit of surfing was our best bet. Then Huey noticed a breeze on the back of his neck, apparently coming from under the exposed tree roots. He shuffled around a bit and suddenly shouted "Hey, there's a gap behind this big root". I rushed over and sure enough there was a three-foot-high, but fairly narrow, gap with a draught coming from it.

This must be where air comes in to a cave system, I thought. Huey said that it might be connected to that other chamber and that it could be wide enough for us to get through. He wriggled part-way through the gap and said that he was looking into what appeared to be the start of a narrow winding passage. He couldn't go in because there was not much light from the entrance and we hadn't got a torch with us. "This does look promising," said Huey, "It's getting a bit dark now but we should come back tomorrow morning with torches and some gear to see how far we can get."

That night we were pretty fired up with enthusiasm and my wine cellar took a bit of a hit. The next day we were up at 'sparrows fart' eager to go. We chucked torches, spare batteries, Huey's potholing gear and some of old Harry's gear into the ute, together with plenty of water and food, expecting it to be a long day. We also took some timber and steel pickets in case we needed props and we threw in some cord, rope, hammers, chisels and wrecking bars for good measure. We also took mobile phones and a digital camera. We were well prepared.

Huey took charge when we got there, which was okay by me. He was the spelunker - the potholing guru.

He took a shovel and dug away some more of the sand and loose rock from around the gap. Within no time at all he pronounced it big enough for us to easily get through and said he could see a good passage beyond, in the light of his torch. He gave me a hank of cord which he said was about twenty metres long. "Now," he said, "grab that cord and tie a secure loop knot in it about every metre". I remember thinking he had lost the plot. "What the hell for?" I said. "Cos I'm going in alone at first and tying one end to my belt. You are going to count how many knots go through with me. When I come out, I want to know how far in I've been. Also, if I get into trouble, you'll know how far you have to come to rescue me." I muttered something about Hansel and Gretel, but I could see the sense in it. I was eager to have a look for myself but Huey petulantly reminded me that I went first all those years ago, so now it was his turn.

He went in with a wrecking bar, mallet, cold chisel and his camera. The cord moved in quickly for about four metres and then stopped. I could hear distant cursing and swearing and the sound of a hammer and chisel on rock. After a while the cord moved again, but slowly and in fits and starts. I couldn't hear anything. I was to find our later that negotiating the passage was not easy, there were narrow places and rock falls and he had had to wriggle on his stomach at one point.

After about an hour the cord stopped moving altogether. 'He's got as far as he can go', I thought. About fifteen metres of cord had gone in.

Then, nothing. I sat and waited for another hour, wondering how long to leave it before going in to find him. Although Huey said that I was to stay outside in case he needed help, I was sick of waiting and a bit concerned, so I decided to go in a little way and call out to see if I could get a response. The first five metres was a tight squeeze but not too difficult. Then the cord disappeared under an overhang. I looked under and saw what looked like an incredibly tight passage; just a slit under the rock. Huey must have gone through but, being the coward that I am, I reasoned that it wouldn't be sensible for me to go any further, bearing in mind that nobody knew we were here.

So, I yelled through the hole as loud as I could. Huey immediately answered and asked me what the hell I was shouting for. He was at the other side of the slit and just about to come back through.

He soon popped out of the hole, flushed and excited. He said there was definitely something weird in there. He'd found the strange formation again, but presumably the other end. He said it was a bit rounded, not flat like the other end. He had managed to slip along the side a little way and got the impression that it was flat sided. He could feel the air going through, presuming it to be going through to the other cave and into the upper chamber.

He said that this end also had stalagmites touching it but that the object itself seemed to be un-corroded. Not metal, more like carbon fibre/metal laminate if anything. It seemed warmer to touch than the surrounding rock. He said he has dozens of good digital photos from all angles.

Despite being scared stiff of being trapped by falling rock I was determined to go in and have a look for myself. He said there were one or two climbs and a couple of dead-end passages but he had unhooked the cord and left it there so I just had to follow it. He said the first slit was the only really difficult bit and I would just have to wriggle through on my belly. He said he would wait behind for safety reasons.

I shoved my torch through first and inched through the passage. I remember thinking that it must have taken a lot of courage for Huey to do this when he didn't know if he could get through and might have got stuck and unable to get back.

The rest of the journey was slow and difficult in parts but I did it in about twenty minutes. I realised why it had taken Huey so long; he had obviously tried a few dead-end passages that branched off, before finding the right one.

I didn't realise I was there until I saw the end on the cord. Then I shone my torch around and saw it. I just gawped at first. It really was a bit weird. Then I went up and touched it and, sure enough, it didn't feel cold and clammy like the rocks. It really did look artificial but I realised that it must have been there for a very long time, unless it was an elaborate hoax. I spent a long time staring at it and wondering how it could have formed, or got there.

Huey was hopping around when I got back out. "What took you so long?" he said.

He was all for getting a Bobcat excavator and digging out the side of the hill. He had estimated the size of the object and reckoned that it would probably fit on a semi-trailer flatbed if we could drag it out to the road.

"Whoa", I said. "We ought to be a little bit cautious about this. We need to find out what it is first. It might be dangerous. Before we tell anyone or try to get some help, we should think carefully about it. Old Harry was probably right not to say anything all those years ago and there is no hurry, it won't go away. Just imagine what would happen if the tabloid press got hold of this. Sensationalist publicity, scaremongering rumours, people crawling all over the place, loss of privacy, drop real estate value if it's thought to be a site of unexploded ordnance and, ultimately, ridicule if there is nothing to it."

We then set into arguing again like the old days. Huey all gung-ho and ready to go; me all caution. We were getting nowhere to I settled it by churlishly by pointing out that it was my place, after all.

"Right", he said, "we'll investigate it ourselves. We'll go up to Perth to hire Geiger counter and stethoscope".

That night we had a good look at all Huey's pictures but were none the wiser. The next morning, we went up to Perth for some supplies, bought a cheap stethoscope and hired a Geiger counter.

In the afternoon we both went through the cave for a closer examination. Disappointingly we could detect no sound through the stethoscope although when we tapped it there was a slightly hollow ring. The Geiger counter reacted no differently from the background radiation so we were a bit relieved that we had not been in contact with anything radioactive.

Huey then took samples of the stalagmites and the soil around, temperature readings, and attempted to take scrapings from the surface of the object, but to no avail. He said he would test what he had in his lab, back in the UK.

I dropped Huey off at his mother's place the next day and called in at Joondalup City shopping mall on the way back for food and other supplies. I was planning to settle in at home for a while to do some thinking about the mystery we had uncovered and, more broadly, the direction my life was taking - in other words, to decide what to do next.

I got back to the homestead mid-afternoon and as I went down the driveway, I saw a large long-wheelbase SUV parked by the sheds. Funny, I thought, not expecting any visitors.

As I pulled up a tall thin fellow detached himself from one of my veranda chairs and walked over to me. He was dressed a bit like a faux farmer in beige chinos, zip sided brown leather boots, check shirt and Akubra hat - all very neat and clean. I noticed that his boots appeared hardly worn; no scratches or scuffs, looked like he had been dressed for a movie part.

"Hello" he said, "Mr Mortimer?" I nodded and waited for him to introduce himself. "Sorry to arrive unannounced, but I was in the area and I stopped by hoping to catch you. Leon Chisholm is my name." He offered his hand, and I shook it. Surprisingly firm handshake for a city slicker, I thought.

He went on to say that for some years now he and his colleagues had been looking for a specific type of property to buy or lease in the area. He said they had spoken to Mr Lees on a number of occasions over the last few years to see if he was interested in selling or leasing the property. For a moment I didn't know who he was talking about, then I remembered that old Harry was Harry Lees. I'd always called him just 'Harry'.

Real estate agents, I thought, but bloody persistent if they had been bothering old Harry for years. Most odd. So I just said "Oh". He said that he had heard that Harry had passed away and left the property to me. He offered his condolences, and said that Harry was a canny character. Apparently, he had never said 'no' to the offers, he had just said 'maybe', when I get too old to look after the place, I might consider a lease. "Yes" I said, "he wasn't an easy man to pin down, and he had a determined streak".

"Have you got time to have a chat?" he asked. I really wasn't in the mood for visitors, especially real estate agents, but I was a little curious as to what the place might be worth on the market today. So, I invited him into the kitchen and gave him a cold drink whilst I unpacked and stowed the food.

We sat at the kitchen table and I asked him which real estate company he represented. He gave a short laugh and said "No, no, I'm not in real estate. We were making offers to Mr Lees on our own behalf. We want the property for our own use and we were wondering what your plans are for it. In other words, we would like to make similar offers to you if you are interested". I told him that I had just moved in and was quite contented here - that it suited me very well. I went on to say that I was sure there would have been many opportunities to buy or lease other similar properties in this area over the past few years. I asked him why they hadn't done so, when Harry turned them down.

He said "No, this property is ideal for our purposes - others wouldn't be".

Odd, I thought, so I asked him what business he was in, and what they wanted the property for. After what seemed like a long pause, he said that they were in mining and engineering and needed a peaceful country property for rest and recreation for their staff, amongst other things. He said that some of them were keen cavers, and he'd heard that there were a few caves in the area and probably on this property. "If we took a lease, with your permission we would carry out extensions and improvements to the premises," he said, "and there is the space to do that. Also, it is quiet and private here." He went on to say that they were very, very keen to acquire or lease my property, and that the offers would reflect that keenness. "I realise that I have sprung this on you without notice but all I ask, Mr Mortimer, is that you take my contact details and think it over. Just give me a call on this number and I'll come out and see you to discuss specifics." Whereupon he handed me a plain white card with just his name and a phone number, no business name. He mumbled something about the cards being temporary.

He then said he wouldn't keep me any longer and abruptly got up and left. 'Not exactly the hard sell' I thought after he had gone. That bit about the caves got me thinking. Had old Harry let the cat out of the bag, I wondered. I decided not to contact him for the moment; just see what developed.

Much later I realised that they already had a 'Plan B' in progress, in case I wouldn't lease or sell.

A few days later I got an email from Huey saying that the lab analyses had turned up nothing unusual, just typical karst limestone and speleothem material, mainly calcium carbonate. That allayed some of my fears that there might be something dangerous about the thing in the cave, but I decided that I would have to solve the mystery of what it actually was at some future time. I emailed Huey to thank him, and I made a promise to do a follow-up investigation with him the next time he was in Perth.

What I wasn't to know was that the mystery had already been solved by others, and that I would get my answers without having to excavate.

I decided that it was time I started looking for gainful employment, then I remembered the cancelled meeting with that fellow Booth, the month before last, and decided to give him a call. I fished out his card and gave him a ring to see if his job offer was still open. When I spoke to him, I was surprised to find that he seemed pleased to hear from me, despite the two months delay. He asked me if I would come over to see him as soon as possible - the next day if I was free.

I was, so I said okay.