The Bricknells were a-twitter. Angelica was distraught that Steve hadn't turned up. Who cared about a horse, where was Steve.

Who was Steve? Zak asked. Angelica said he was her business manager. What business? Zak asked. None of yours, Angelica tartly said.

'Right,' Zak said, 'about now it has dawned on the thickest passenger that this is all fiction. They'll be smiling. So lunch is next. Everyone gets the afternoon to relax. Our next scene is during drinks before dinner. That's the one we rehearsed before Nell came. Right. We may have to change things a bit as we go along, so we'll do the rest of the final walk-throughs in one of the bedrooms, a day at a time.'

The others thought this reasonable and began to put on their coats.

'Don't you have a script?' I asked Zak.

'Not formal works to learn, if that's what you mean. No. We all know what we've got to establish in each scene, and we improvise. When we plan a mystery, the actors get a brief outline of what's going to happen and basically what sort of people they are, then they invent their own imaginary life stories, so that if any passenger asks questions in conversations, they have the answers ready. I'd advise you to do it, too. Invent a background, a childhood… as near as possible to the real thing is always easiest.'

Thanks for the tip,' I said. 'Will you let me know your plans each day, and also tell me instantly if anything odd happens you don't expect? Even small things, really.'

'Yes, sure. Ask Nell, too. She knows the story. And there are some actors who weren't here today because they don't get activated until later on the trip. They're on the passenger list. Nell will point them out.'

He stifled a yawn and looked suddenly very tired, a complete contrast to two minutes earlier, and I suspected he was one of those people who could turn energy on and off like a tap. One of Aunt Viv's best friends had been an elderly actor who could walk down to the theatre like a tired old pensioner and go out on the stage and make the audience's hair stand on end with his power.

David Flynn, offering me a lift if I needed one, was beginning to move with a sort of lassitude that one would never have seen in Zak. He picked up Nell's large envelope, opened it and distributed its contents to the others: luggage labels saying 'Merry amp; Co', and photocopied sheets of 'Information and Advice to Passengers'.

Scene dressing, I supposed. I asked him if he would be going anywhere near the Merry amp; Co office and he said he would detour that way and was as good as his word.

'Do you do this all the time?' I asked on the way.

'Act, do you mean? Or mysteries?'

'Either.'

'Anything I'm offered,' he said frankly. 'Plays. Commercials. Bit parts in series. But I do mostly mysteries now that they're so popular, and nearly all for Merry amp; Co. I write the stories to suit the occasion. I was engaged for a doctors' convention last week, so we did a medical crime. Just now it's racing. Next month I've got to think up something for a fishing club weekend train trip to Halifax. It keeps me employed. It pays the bills. It's quite good fun. It's not Stratford-upon-Avon.'

'What about the other actors?' I asked. 'The ones in the garage.'

'Much the same. It's work. They like the train trips, even if it does mean shouting all the scenes against the wheel noise when we're going along, because the dining cars are so long. Not by any means the right shape for a stage. We don't always use the same actors, it depends on the characters, but they're all friendly, we never take anyone who can't get along. It's essential to be tolerant and generous, to make our sort of improvisation work.'

'I'd no idea mysteries were such an industry.'

He gave a small sideways smile. 'They have a lot in England too, these days.'

'Um… I said, as he braked to a halt outside the Merry amp; Co offices. 'How English do I sound to you?'

'Very. An educated Englishman in an expensive suit.'

'Well, the original plan was for me to go on the train as a wealthy owner. What would you think of my accent if I were dressed as a waiter in a deep-yellow waistcoat?'

'Harvest gold, that's what they call that colour,' he said thoughtfully. 'I wouldn't notice your accent so much, perhaps. There are thousands of English immigrants in this country, after all. You'll get by all right, I should think.'

I thanked him for the lift and got out of the car. He yawned and turned that into a laugh, but I reckoned the tiredness was real. 'See you Sunday, Tommy,' he said, and I dryly said, 'Sure thing, Zak.' He drove away with a smile and I went into the Merry amp; Co office where the earlier calm had broken up into loud frenetic activity on several telephones.

'How could twenty-five of our bikers all burst their tyres at once?'

'They won't reach Nuits St George tonight.'

'Any suggestions for alternative hotels?'

'Where do we find fifty new tyres, assorted, in France? They've cut them to ribbons, they say.'

'It was sabotage. It has to be.'

'They rode over a cattle-grid which had spikes.'

Nell was sitting at her desk talking on her telephone, one hand pressed to her free ear to block out the clamour.

'Why didn't the fools pick up their bikes and walk across?'

'Nobody told them. It was a new grid. Where is Nuits St George? Can't we get a bus to go and pick up the bikes? What bus company do we use in that part of France?'

'Why isn't our French office dealing with all this?'

I sat on Nell's client chair and waited. The hubbub subsided: the crisis was sorted. Somewhere in Burgundy, the bikers would be transported to their dinners on sturdier wheels, and new tyres would be found in the morning.

Nell put her receiver down.

'You arrange cycling tours?' I said.

'Sure. And trips up Everest. Not me personally, I do mysteries. Do you need something?'

'Instructions.'

'Oh, yes. I talked to VIA. No problems.'

VIA Rail, I had discovered, was the company that operated Canada 's passenger trains, which didn't mean that it owned the rails or the stations. Nothing was simple on the railways.

'VIA,' Nell said, 'are expecting you to turn up at Union Station tomorrow morning at ten to get fitted for a uniform. Here's who you ask for.' She passed me a slip of paper. 'They've got hand-picked service people going on this trip, and they'll show you what to do when you meet them at the station on Sunday morning. You'll board the train with them.'

'What time?' I asked.

'The train comes into the station soon after eleven. The chefs and crew board soon after. Passengers board at eleven-thirty, after the reception in the station itself. The train leaves at twelve. That's thirty-five minutes earlier than the regular daily train, the Canadian, which will be on our heels as far as Winnipeg.'

'And the horses will have boarded, I gather, out in a loading area.'

'Yes, at Mimico, about six miles away. That's where they do maintenance and cleaning and put the trains together. Everything will be loaded there. Food, wine, flowers, everything for the owners.'

'And the grooms?'

'No, not them. They're being shipped back to the station by bus after they've settled the horses in. And you might like to know we've another addition to the train, a cousin of our boss, name of Leslie Brown, who's going as horsemaster, to oversee the horses and the grooms and keep everything up that end in good order.'

'Which end?'

'Behind the engine. Apparently horses travel better there. No swaying.'

While she was talking, she was sorting postcards into piles: postcards with names and numbers on.

'Do you have a plan of the train?' I asked.

She glanced up briefly and didn't exactly say I was a thundering nuisance, but looked as if she thought it. Still, she shuffled through a pile of papers, pulled out a single sheet and pushed it across the desk towards me.