'Will do,' said Harry. He put the phone down and looked up the headmaster's number in his telephone book.

'Don't worry, darling, he's no longer a schoolboy, as you keep reminding me,' he said when he saw the anxious look on Emma's face. 'I'm sure there'll be a simple explanation.' He dialled Beechcroft 117, and while he waited for someone to answer, he took his wife in his arms.

'Dr Banks-Williams speaking.'

'Headmaster, it's Harry Clifton. I'm sorry to bother you after the school has broken up, but I wondered if you had any idea where my son Sebastian might be.'

'I've no idea, Mr Clifton. I haven't seen him since he was rusticated earlier in the week.'

'Rusticated?'

'I'm afraid so, Mr Clifton. I fear I was left with little choice.'

'But what did he do to deserve that?'

'Several minor offences, including smoking.'

'And any major offences?'

'He was caught drinking in his study with a serving maid.'

'And that was considered worthy of rustication?'

'I might have turned a blind eye, as it was the last week of term, but unfortunately neither of them had any clothes on.'

Harry stifled a laugh, and was only glad that Emma couldn't hear the other side of the conversation.

'When he reported to me the following day, I told him that after some deliberation, and having consulted his housemaster, I was left with no choice but to rusticate him. I then gave him a letter which I asked him to pass on to you. It's clear that he has not done so.'

'But where can he be?' asked Harry, becoming anxious for the first time.

'I've no idea. All I can tell you is that his housemaster supplied him with a third-class single ticket to Temple Meads, and I assumed that would be the last I would see of him. However, I had to travel up to London that afternoon to attend an Old Boys' reunion dinner, and to my surprise I found him travelling on the same train.'

'Did you ask him why he was going to London?'

'I would have done so,' said the headmaster dryly, 'if he hadn't left the carriage the moment he saw me.'

'Why would he do that?'

'Possibly because he was smoking, and I'd previously warned him that if he broke any more school rules during term time he would be expelled. And he knew only too well that would mean me calling the admissions tutor at Cambridge and recommending that his prize scholarship be withdrawn.'

'And did you?'

'No, I did not. You have my wife to thank for that. If I'd had my way, he would have been expelled and forfeited his place at Cambridge.'

'For smoking, when he wasn't even on the school premises?'

'That was not his only offence. He was also occupying a first-class carriage when he didn't have the money for a first-class ticket, and earlier he'd lied to his housemaster about going straight back to Bristol. That, on top of his other offences, would have been quite enough to convince me that he was unworthy of a place at my old university. I've no doubt I will live to regret my leniency.'

'And that was the last you saw of him?' said Harry, trying to remain calm.

'Yes, and it's the last I want to see of him,' said the headmaster, before putting the phone down.

Harry reported the other end of the conversation to Emma, only leaving out the incident with the serving maid.

'But where could he be now?' asked Emma anxiously.

'The first thing I'm going to do is ring Giles back and let him know what's happened, before we decide what to do next.' Harry picked up the phone again, and took some time repeating the headmaster's conversation almost verbatim.

Giles was silent for a few moments. 'It's not hard to work out what must have been going through Seb's mind after Banks-Williams found him on the train.'

'Well I'm damned if I can work it out,' said Harry.

'Put yourself in his shoes,' said Giles. 'He thinks that because the headmaster's caught him smoking while travelling up to London without permission, he must have been expelled, and lost his place at Cambridge. I suspect you'll find he's afraid of returning home and having to face you and Emma.'

'Well, that's no longer the problem, but we still have to find him and let him know. If I drive up to London straight away, can I stay at Smith Square?'

'Of course you can, but that doesn't make any sense, Harry. You should stay at the Manor House with Emma. I'll go up to London and then we'll have both ends covered.'

'But you and Gwyneth are meant to be spending a weekend together, in case you'd forgotten.'

'And Seb's still my nephew, Harry, in case you've forgotten.'

'Thank you,' said Harry.

'I'll ring you as soon as I get to London.'

'You said you had some news?'

'It's not important. Well, not as important as finding Seb.'

Giles drove up to London that evening, and when he arrived in Smith Square his housekeeper confirmed that Sebastian hadn't been in touch.

Once Giles had passed that news on to Harry, his next call was to the assistant commissioner at Scotland Yard. He couldn't have been more sympathetic, but he pointed out that a dozen children were reported missing in London every day, and most of them were a lot younger than Sebastian. In a city with a population of eight million, it was like looking for a needle in a haystack. But he said he would put out an alert to every police district in the Met area.

Harry and Emma sat up late into the night calling Sebastian's grandmother Maisie, his aunt Grace, Deakins, Ross Buchanan, Griff Haskins, and even Miss Parish, as they tried to find out if Sebastian had been in touch with any of them. Harry spoke to Giles several times the following day, but he had nothing new to report. A needle in a haystack, he repeated.

'How's Emma bearing up?'

'Not well. She fears the worst as each hour passes.'

'And Jessica?'

'Inconsolable.'

'I'll call you the moment I hear anything.'

The following afternoon, Giles rang Harry from the House of Commons to tell him he was on his way to Paddington to visit a woman who'd asked to see him because she had news about Sebastian.

Harry and Emma sat by the phone, expecting Giles to ring back within the hour, but he didn't call again until just after nine o'clock that evening.

'Tell me he's fit and well,' said Emma after she'd grabbed the phone out of Harry's hand.

'He's fit and well,' said Giles, 'but I'm afraid that's the only good news. He's on his way to Buenos Aires.'

'What are you talking about?' said Emma. 'Why would Seb want to go to Buenos Aires?'

'I've no idea. All I can tell you is that he's on board the SS South America with someone called Pedro Martinez, the father of one of his school friends.'

'Bruno,' said Emma. 'Is he on board as well?'

'No, he can't be, because I saw him at his house in Eaton Square.'

'We'll drive up to London immediately,' said Emma. 'Then we can visit Bruno first thing in the morning.'

'I don't think that would be wise in the circumstances,' said Giles.

'Why not?' demanded Emma.