He nodded at the reply he heard, took off the headset and gave it to me.

'You are talking to the despatcher in Schreiber,' he said, 'that's ahead of us, this side of Thunder Bay -and he can radio straight to the Canadian following us. You can hear the despatcher without doing anything. To transmit, press the button.' He pointed, and was gone.

I put on the headset and sat in his chair and presently into my ears a disembodied voice said, 'Are you there?'

I pressed the button, 'Yes.'

'Tell George I got the Canadian and it will stop in Cartier. There's a CP freight train due behind it but I got Sudbury in time and it isn't leaving there. No one is happy. Tell George to pick up that car and get the hell out.'

I pressed the button. 'Right,' I said.

'Who are you?' asked the voice.

'One of the attendants.'

She said, 'Huh,' and was quiet.

The Great Transcontinental Mystery Race Train began to slow down and soon came to a smooth stop. Almost in the same instant, George was back in his doorway.

'Tell the despatcher we've stopped and are going back,' he said, when I'd relayed the messages. 'We're eleven point two miles out of Cartier, between Benny and Stralak, which means in an uninhabited wilderness. You stay here, eh?' And he was gone again, this time towards the excitement in the tail.

I gave his message to the despatcher and added, 'We're reversing now, going slowly.'

'Let me know when you find the car.'

'Yes.'

It was pitch dark through the windows; no light in the wilderness. I heard afterwards from a lot of excited chattering in the dining room that George had stood alone outside the rear door of the dome car on the brink of space, directing a bright hand-held torch beam down the track. Heard that he had a walkie-talkie radio on which he could give the engineer instructions to slow down further, and to stop.

He found the Lorrimores' car about a mile and a half out of Cartier. The whole train stopped while he jumped down from the dome car and went to look at the laggard. There was a long pause from my point of view, while the lights began nickering in the office and the train exceedingly slowly reversed, before stopping again and going into a sudden jerk. Then we started forwards slowly, and thenfaster, and the lights stopped flickering, and soon after that George appeared in his office looking grim, all chuckles extinguished.

'What's the matter,' I said.

'Nothing,' he said violently, 'that's what's the matter.' He stretched out a hand for the headset which I gave him.

He spoke into it. 'This is George. We picked up the Lorrimores' car at one point three miles west of Cartier. There was no failure in the linkage.' He listened. 'That's what I said. Who the hell do they have working in Cartier, eh? Someone uncoupled that car at Cartier and rigged some way of pulling it out of the station into the darkness before releasing it. The brakes weren't on. You tell Cartier to send someone right away down the track looking for a rope or some such, eh? The steam heat pipe wasn't broken, it had been unlocked. That's what I said. The valve was closed. It was no goddam accident, no goddam mechanical failure, someone deliberately unhitched that car. If the Lorrimore girl hadn't found out, the Canadian would have crashed into it. No, maybe not at high speed, but at twenty-five, thirty miles an hour the Canadian can do a lot of damage. Would have made matchsticks of the private car. Might have killed the Canadian engineers, or even derailed the train. You tell them to start looking, eh?'

He took off the headset and stared at me with rage.

'Would you,' he said, 'know how to uncouple one car from another?'

'No, of course not.'

'It takes a railwayman.' He glared. 'A railwayman! It's like a mechanic letting someone drive off in a car with loose wheel nuts. It's criminal, eh?'

'Yes.'

'A hundred years ago,' he said furiously, 'they designed a system to prevent cars that had broken loose from running backwards and crashing into things. The brakes go on automatically in a runaway.' He glared. 'That system had been by-passed. The Lorrimores' brakes weren't on. That car was deliberately released on level ground, eh? I don't understand it. What was the point?'

'Maybe someone doesn't like the Lorrimores,' I suggested.

'We'll find the bastard,' he said, not listening. ‘There can't be many in Cartier who know trains.'

'Do you get much sabotage?' I asked.

'Not like this. Not often. Once or twice in the past. But it's mostly vandals. A kid or two throwing rocks off a bridge. Some stealing, eh?’

He was affronted, I saw, by the treachery of one of his own kind. He took it personally. He was in a way ashamed, as one is if one's countrymen behave badly abroad.

I asked him about his communication system with the engineer. Why had he gone up the train himself to get it stopped if he had a walkie-talkie?

'It crackles if we're going at any speed. It's better to talk face to face.'

A light flashed on the ship-to-shore radio and he replaced his headset.

'George here,' he said, and listened. He looked at his watch and frowned. 'Yes. Right. Understood.' He took off the headset, shaking his head. 'They're not going to go along the track looking for a rope until both the Canadian and the freight train have been through. If our saboteur's got an ounce of sense, by that time there won't be anything incriminating to find.'

'Probably not already,' I said. 'It's getting on for an hour since we left Cartier.'

'Yeah,' he said. His good humour was trickling back despite his anger, the gleam of irony again in his eye. 'Better than that fellow's fake mystery, eh?'

'Yes…' I said, thinking. 'Is the steam pipe the only thing connecting one car to the next? Except the links, of course.'

That's right.'

'What about electricity… and water?’

He shook his head. 'Each car makes its own electricity. Self contained. They have generators under the floors… like dynamos on bicycles… that make electricity from the wheels going round. The problem is that when we're going slowly, the lights flicker. Then there are batteries for when we're stopped, but they'd only last for forty-five minutes, eh?, if we weren't plugged into the ground supply at a station. After that we're down to emergency lighting, just the aisle lights and not much else for about four hours, then we're in the dark. ''And water?' I asked.

'It's in the roof.'

'Really?' I said, surprised.

He patiently explained. 'At city stations, we have water hydrants every eighty-five feet, the length of the cars. One to each car. Also the main electricity, same thing, eh? Anyway, the water goes up under pressure into the tanks in the roof and feeds down again to the washrooms by gravity.'

Fascinating, I thought. And it had made unhitching the Lorrimores' car a comparatively quick and easy job.

'The new cars,' George said, 'will be heated by electricity, not steam, so we'll be doing away with the steam pipe, eh? And they'll have tanks for the sewage, which now drops straight down on to the tracks, of course.'

' Canada 's railways,' I said politely, 'will be the envy of the world.'

He chuckled. 'The trains between Montreal and Toronto are late three-quarters of the time and the new engines break down regularly. The old rolling stock, like this train, is great.'

He picked up the headset again. I raised a hand in farewell and went back to the dining room where the real mystery had easily usurped Zak's, though some were sure it was part of the plot.

Xanthe had cheered up remarkably through being the centre of sympathetic attention, and Filmer was telling Mercer Lorrimore he should sue the railway company for millions of dollars for negligence. The near-disaster had galvanized the general consciousness to a higher adrenaline level, probably because Xanthe had not, in fact, been carried off like Angelica.