I pondered his 'stopping' activities, his feud with Sandy Mason, his disgrace with Tudor, his obscure threatening notes. I thought about the internal workings of the weighing-room, where only valets, jockeys, and officials are allowed in the changing rooms, and trainers and owners are confined to the weighing room itself: while the press and the public may not enter at all.

If the 'Bolingbroke, this week' note was to be believed, Joe would already have received his punishment, because 'this, week' was already last week. Yet I came to the conclusion that I would see him alive and well at Bristol on the following day, even if not in the best of spirits. For, by the time I reached home, I knew I could tell him who had written the notes, though I wasn't sure I was going to.

Sleep produces the answers to puzzles in the most amazing way. I went to bed on Wednesday night thinking I had spent a more or less fruitless morning in Brighton. But I woke on Thursday morning with a name in my mind and the knowledge that I had seen it before, and where. I went downstairs in my dressing-gown to Bill's desk, and took out the betting tickets he had saved for Henry. I shuffled through them, and found what I wanted. Three of them bore the name L. C. PERTH.

I turned them over. On their backs Bill had pencilled the name of a horse, the amount of his bet, and the date. He was always methodical. I took all the tickets up to my room, and looked up the races in the form book. I remembered many casual snatches of conversation. And a lot of things became clear to me.

But not enough, not enough.

It poured with rain at Bristol, a cold, steady unrelenting wetness which took most of the pleasure out of racing.

Kate sent a message that she was not coming because of the weather, which sounded unlike her, and I wondered what sort of pressure Aunt Deb had used to keep her at home.

The main gossip in the weighing-room concerned Joe Nantwich. The Stewards had held an inquiry into his behaviour during the last race on Champion Hurdle day, and had, in the official phrase, 'severely cautioned him as to his future riding'. It was generally considered that he was very lucky indeed to have got off so lightly, in view of his past record.

Joe himself was almost as cocky as ever. From a distance his round pink face showed no traces of the fear or drunkenness which had made a sodden mess of him at Cheltenham. Yet I was told that he had spent the preceding Friday and Saturday and most of Sunday in the Turkish baths, scared out of his wits. He had drunk himself silly and sweated it off alternately during the whole of that time, confiding to the attendants in tears that he was safe with them, and refusing to get dressed and go home.

The authority for this story, and one who gave it its full flavour, was Sandy, who had happened, he said, to go into the Turkish baths on Sunday morning to lose a few pounds for Monday's racing.

I found Joe reading the notices. He was whistling through his teeth.

'Well, Joe,' I said, 'what makes you so cheerful?'

'Everything.' He smirked. At close quarters I could see the fine lines round his mouth and the slightly bloodshot eyes, but his experiences had left no other signs of strain. 'I didn't get suspended by the Stewards. And I got paid for losing that race.'

'You what?' I exclaimed.

'I got paid. You know, I told you. The packet of money. It came this morning. A hundred quid.' I stared at him. 'Well, I did what I was told, didn't I?' he said aggrievedly.

'I suppose you did,' I agreed, weakly.

'And another thing, those threatening notes. I fooled them you know. I stayed in the Turkish baths all over the week-end, and they couldn't harm me there. I got off scot free,' said Joe triumphantly, as if 'this week' could not be altered to 'next week'. He did not realize either that he had already taken his punishment, that there are other agonies than physical ones. He had suffered a week of acute anxiety, followed by three days of paralysing fear, and he thought he had got off scot free.

'I'm glad you think so,' I said, mildly. 'Joe, answer me a question. The man who rings you up to tell you what horse not to win on, what does his voice sound like?'

'You couldn't tell who it is, not by listening to him. It might be anybody. It's a soft voice, and sort of fuzzy. Almost a whisper, sometimes, as if he were afraid of being overheard. But what does it matter?' said Joe. 'As long as he delivers the lolly he can croak like a frog for all I care.'

'Do you mean you'll stop another horse, if he asks you to?' I said.

'I might do. Or I might not,' said Joe, belatedly deciding that he had been speaking much too freely. With a sly, sidelong look at me he edged away into the changing room. His resilience was fantastic.

Pete and Dane were discussing the day's plans not far away, and I went over to them. Pete was cursing the weather and saying it would play merry hell with the going, but that Palindrome, all the same, should be able to act on it.

'Go to the front at half way, and nothing else will be able to come to you. They're a poor lot. As far as I can see, you're a dead cert.'

'That's good,' I said, automatically, and then remembered with a mental wince that Admiral had been a dead cert at Maidenhead.

Dane asked me if I had enjoyed my stay with Kate and did not look too overjoyed by my enthusiastic answer.

'Curses on your head, pal, if you have cut me out with Kate.' He said it in a mock ferocious voice, but I had an uncomfortable feeling that he meant it. Could a friendship survive between two men who were in love with the same girl? Suddenly at that moment, I didn't know; for I saw in Dane's familiar handsome face a passing flash of enmity. It was as disconcerting as a rock turning to quicksand. And I went rather thoughtfully into the changing-room to find Sandy.

He was standing by the window, gazing through the curtain of rain which streamed down the glass. He had changed into colours for the first race, and was looking out towards the parade ring, where two miserable-looking horses were being led round by dripping, mackintoshed stable lads.

'We'll need windscreen wipers on our goggles in this little lot,' he remarked, with unabashed good spirits. 'Anyone for a mud bath? Blimey, it's enough to discourage ducks.'

'How did you enjoy your Turkish bath on Sunday?' I asked, smiling.

'Oh, you heard about that, did you?'

'I think everyone has heard about it,' I said.

'Good. Serve the little bastard right,' said Sandy, grinning hugely.

'How did you know where to find him?' I asked.

'Asked his mother-' Sandy broke off in the middle of the word, and his eyes widened.

'Yes,' I said. 'You sent him those threatening Bolingbroke notes.'

'And what,' said Sandy, with good humour, 'makes you think so?'

'You like practical jokes, and you dislike Joe,' I said. 'The first note he received was put into his jacket while it hung in the changing-room at Plumpton, so it had to be a jockey or a valet or an official who did it. It couldn't have been a bookmaker or a trainer or an owner or any member of the public. So I began to think that perhaps the person who planted the note in Joe's pocket was not the person who was paying him to stop horses. That person has, strangely enough, exacted no revenge at all. But I asked myself who else would be interested in tormenting Joe, and I came to you. You knew before the race that Joe was not supposed to win on Bolingbroke. When he won you told him you'd lost a lot of money, and you'd get even with him. And I guess you have. You even tracked him down to enjoy seeing him suffer.'

'Revenge is sweet, and all that. Well, it's a fair cop,' said Sandy. 'Though how you know such a lot beats me.'