I might have known that's what they'd do. Of course I'd heard about it, even laughed when it was some other kid who'd slipped up and fallen asleep at the switch. Literally, in this case.
The trouble is, it's one thing to play pranks when the only thing at stake is wounded vanity and hurt feelings (though come to think of it, the chances of someone getting hurt were still not that inconsiderable). It's quite another when it's already a matter of life and death.
I had no idea that's what it was, at first. How could I? That's the whole point of the joke, really. What you do is a bit like a card trick, really. You know, the ones where you ask someone to pick a card, any card -- only there's something in the way you're holding them that makes your victim choose the one you had in mind for them all along.
In this case it was suits and oxygen tanks. You leave them all higgledy-piggledy, so that everybody chooses seemingly at random, but actually you've already monkeyed with the breathable air gauges on one of them so that the mixture's all messed up.
Result: a kind of stange euphoria, shading off into hallucination and (I guess, eventually) unconsciousness and death. Unless someone finds you first, that is.
When I set off I was alone, but by the time I'd gone a mile or two I had at least two companions with me (I say at least, because I was pretty sure there were more creeping along just out of eyeshot, visible only through their movements in the shadows).
It was therefore kind of a comfort that they were warriors. One was a muscular, practically naked human about my height and weight. He told me he was looking for his girlfriend. Dejah Thoris, I think he said her name was.
The other was even stranger. Roughly four metres tall, with four arms and a green skin (I guess I must have seen something like him in a picture once -- I'm not really one for bug-eyed monsters as a general rule).
They were good to talk to, to tell you the truth. I mean, it wasn't all that easy to say just what I was looking for, but they seemed to understand that. The concept of a quest against overwhelming odds made perfect sense to them.
They told me stories about their past exploits (I wish I could remember half of them), and so we covered miles like that, just strolling along, listening companionably to whoever was discoursing at the time.
Which is not to say that there weren't intervals of silence. They pricked up their ears at every strange sound. On Mars, you see, little ever moves - there's none of that perpetual susurration of dust and subsiding rock you get on earth (or so I'm told).
So sound means danger, especially in the tunnels below the city. They knew that, and I knew that, and so did the strange dog-thing they had with them.
I don't know when I noticed how hard it was getting to keep on walking. I must have been staggering like a drunk, to tell the truth. They were far too polite to comment, but after a while they had to start helping me along.
I'm sure they could have carried me themselves, if they'd been real. They still seem quite real to me, looking back, but I didn't know then that my air had been tampered with.
So it's like a long dream, the whole memory of that walk, and I really have no way of knowing just when and where I finally collapsed. I couldn't take you there, if that's what you're wondering.
All I can see is water and green grass. Unlikely on Mars, I know, but that's what I'm seeing now.