'Alec! Look there!' She pointed. I looked.

It should have been my turn to gasp, but I was somewhat braced for it: high up, a cruciform shape, somewhat like a bird gliding, but much larger and clearly artificial. A flying machine

I knew that flying machines were impossible; in engineering school I had studied Professor Simon Newcomb's well-known mathematical proof that the efforts of Professor Langley and others to build an aerodyne capable of carrying a man were doomed, useless, because scale theory proved that no such contraption large enough to carry a man could carry a heat-energy plant large enough to lift it off the ground - much less a pa.s.senger.

That was science's final word on a folly and it put a stop to wasting public monies on a will-o'-the-wisp. Research and development money went into airships, where it belonged, with enormous success.

However, in the past few days I had gained a new angle on the idea of 'impossible'. When a veritable flying machine showed up in our sky, I was not greatly surprised.

I think Margrethe held her breath until it pa.s.sed over us and was far toward the horizon. I started to, then forced myself to breathe calmly - it was such a beautiful thing, silvery and sleek and fast. I could not judge its size, but if those dark spots in its side were windows, then it was enormous.

I could not see what pushed it along.

'Alec... is that an airship?'

'No. At least it is not what I meant when I told you about airships. This I would call a "flying machine ".'That's all I can say; I've never seen one before. But I can tell you -one thing, now - something very important.'

'Yes?'

'We are not going to die... and I now know why the ship was sunk.'

'Why, Alec?'

'To keep me from checking a thumbprint.'

Chapter 9.

For I was an hungred, and ye gave me meat: I was thirsty, and ye gave me drink: I was a stranger, and ye took me in.

Matthew 25:35

'OR, TO put it more nearly exactly, the iceberg was there and the collision took place to keep me from checking my thumbprint against the thumbprint on Graham's driver's license. The ship may not have sunk; that may not have been necessary to the scheme.'

Margrethe did not say anything.

So I added gently, 'Go ahead, dear; say it. Get it off your chest; I won't mind. I'm crazy. Paranoid.'

'Alec, I did not say that. I did not think it. I would not.'

'No, you did not say it. But this time my aberration cannot be explained away as "loss of memory". That is, if we saw the same thing. What did you see?'

'I saw something strange in the sky. I heard it, too. You told me that it was a flying machine.'

'Well, I think that is what it should be called - but you can call it a, uh, a "gumpersaggle" for all of me. Something new and strange. What is this gumpersaggle? Describe it.'

'It was something moving in the sky. It came from back that way, then pa.s.sed almost over us, and disappeared there.' (She pointed, a direction I had decided, was north.) 'It was shaped something like a cross, a crucifix. The crosspiece had b.u.mps on it, four I think. The front end had eyes like a whale and the back end had flukes like a whale. A whale with wings - t hat's what it looked like, Alec; a whale flying through the sky!'

'You thought it was alive?'

'Uh, I don't know. I don't think so. I don't know what to think.'

'I don't think it was alive; I think it was a machine. A flying machine. A boat with wings on it. But, either way - a machine or a flying whale - have you- ever in your life seen anything like it?'

'Alec, it was so strange that I have trouble believing that I saw it.'

'I know. But you saw it first and pointed it out to me so I didn't trick you into thinking that you saw it.'

' You wouldn't do that.'

'No, I would not. But I'm glad you saw it first, dearest girl; that means it's real - not something dreamed up in my fevered brain. That thing did not come from the world you are used to... and I can promise you that it is not one of the airships I talked about; it is not from the world I grew up in. So we're now in still a third world.' I sighed. 'The first time it took a twenty-thousand-ton ocean liner to prove to me that I had changed worlds. This time just one sight of something that simply could not exist in my world is all I need to know that they are at it again. They shifted worlds when I was knocked out - I think that's when they did it. As may be, I think they did it to keep me from checking that thumbprint. Paranoia. The delusion that the whole world is a conspiracy. Only it's not a delusion.'

I watched her eyes. 'Well?'

'Alec ... could it possibly be that both of us imagined it? Delirious, perhaps? We've both had a rough experience - you hit your head; I may have hit mine when the iceberg struck.'

'Margrethe, we would not each have the same delirium dream. If you wake up and find that I'm gone, that could be your answer. But I'm not gone; I'm right here. Besides, you would still have to account for an iceberg as far south as we are. Paranoia is a simpler explanation. But the conspiracy is aimed at me; you just had the misfortune to be caught in it. I'm sorry.' (I wasn't really sorry. A raft in the middle of the ocean is no- place to be alone. But with Margrethe it was 'paradise enow.')

'I still think that sharing the same dream is - Alec, there it comes again!' She pointed.

I didn't see anything at first, then I did: A dot that grew into a cruciform shape, a shape that I now identified as 'flying machine'. I watched it grow.

'Margrethe, it must have turned around. Maybe it saw us. Or they saw us. Or he saw us. Whatever.'

'Perhaps.'

As it came closer I saw that it was going to pa.s.s to our right rather than overhead. Margrethe said suddenly, 'It's not the same. one.'

'And it's not a flying whale - unless flying whales hereabouts have wide red stripes down their sides.'

'It's not a whale. I mean "it's not alive". You are right,

Alec; it is a machine. Dear, do you really think it has people inside it? That scares me.'

'I think I would be more scared if it did not have people inside it.' (I remembered a fantastic story translated from the German about a world peopled by nothing but automatic machines - not a pleasant story.) 'Actually, it's good news. We both know now that our seeing the first one was not a dream, not an illusion. That nails down the fact that we are in another world. Therefore we are going to be rescued.'

She said hesitantly, 'I don't quite follow that.'

'That's because you are still trying to avoid calling me paranoid - and thank you, dear, but my being paranoid is the simplest hypothesis. If the joker pulling the strings had intended to kill me, the easy time to do it would have been with the iceberg. Or earlier, with the fire pit. But he 's not out to kill me, at least not now. He's playing with me, cat and mouse. So I'll be rescued. So will you, because we're together. You were with me when the iceberg hit - your bad luck. You're still with me now, so you'll be rescued,your good luck. Don't fight it, dear. I've had some days to get used to it, and I find that it is all right once you relax. Paranoia is the only rational approach to a conspiracy world.'

'But, Alec, the world ought not to he that way,'

'There is no "ought" to it, my love. The essence of philosophy is to accept the universe as it-is, rather than ,try to force it into some preconceived shape.' I added, 'Wups! Don't roll off. You don't want to be a snack for a shark just after we've had proof that we are going to be picked up!'

For the next hour or so nothing happened - unless you count sighting two regal sailfish. The overcast burned away and I began to be anxious for an early rescue; I figured they owed me that much! Not let me get a third-degree sunburn. Margrethe might be able to take a bit more sun than I; she was blonde but she was tanned a warm toast color all over - lovely! But I was raw frog-belly white except for my face and hands - a full day of tropic sun could put me into hospital. Or worse.

The eastern horizon now seemed to show a gray unevenness that could be mountains - or so I kept telling myself, although there isn't much you can see when your viewpoint is about seven inches above water line. If those were indeed mountains or hills, then land was not many miles away. Boats from Mazatlan should be in sight any time now... if Mazatlan was still there in this world. If -

Then another flying machine showed up.