The image of Imogen being roasted was unfortunate on too many levels to contemplate, so Kate let it pass. ‘Could I talk to you about something, Prime Minister?’

‘Of course.’ He tried to smile at her, but it came out as a grimace. ‘Don’t tell me you’ve found the wretched blighter!’

Kate pointed towards the seating area on the other side of his desk, as though this were her office. But he meekly complied. He fell into the sofa with a dull thud. He wasn’t growing any lighter. ‘I feel as if I’m just getting started,’ he said. ‘That’s the absolute bugger of it.’

She let him settle. ‘Could you tell me about your friendship with Sir Alan Brabazon?’

He looked as if he had been shot. ‘What?’ he spluttered.

‘You were great friends once. It would help me to know about that period.’

He shook his head ruefully. ‘He told you, did he?’

Kate wondered why he was making such a meal of this. It wasn’t the world’s best-kept secret that they had been at school together, though few perhaps knew that two of the most powerful men in the country had been in the same year and boarding house – and, more than that, had been the very best of friends. Inseparable, one of their contemporaries had told her. ‘You think he was so upset with me when we fell out that he’s spent the rest of his life working out a way to destroy me?’ He shook his head. ‘You’re going to have to do better than that, Kate.’

‘You did fall out?’

‘Why on earth would it matter now?’

‘We’re at the stage with this, sir, where everything matters. We spoke to one contemporary who said you were inseparable for much of your school career.’

‘I wouldn’t go quite that far. We weren’t shagging each other, if that’s what you’re driving at.’ Why, Kate thought, did everything with this man have to come down to shagging? ‘Boarding school in those days was a rather brutal experience,’ he went on. ‘You needed a sense of humour to get you through. We bonded over that, and I suppose we were close for a while.’

‘Until when?’

‘Look, Kate, does this really matter?’

‘I have no idea.’

‘All right. We fell out in the sixth form because I found his attitude towards my romantic activities a trifle priggish. Alan never found a moral high ground he wasn’t determined to mount.’

‘Would you care to elaborate?’

‘Not much.’ She leant forward, ready to press further. ‘All right!’ He flung his hands up in exasperation. ‘I was a bit of a bounder, no question. I wasn’t too good at letting one girl know I’d had enough of her before moving on to the next. I rather enjoyed my reputation, but he had a sister at the girls’ school next door of whom he was very protective and …’

‘You had an affair with her?’

‘Worse than that. I’d been to Amsterdam one half-term with a friend from home and managed to pick up some crabs.’ He grinned sheepishly. ‘You know …’