‘Sorry about the cake. Shall I call for more hot water?’

‘It’ll be fine with milk and sugar,’ Vic lied. ‘I could drink anything right now.’

As they returned outside, Johnnie announced: ‘Listen up, chaps: this is Mr Mackensie, who has just joined us from Cambridge University, no less.’ A murmur of approval.

They seemed to fall into two types. Some looked like standard academics, dressed in scruffy suits or tweed jackets over shirts and ties, and wearing spectacles. At least he looked the part well enough, he thought. Others were more practical-looking chaps in khaki overalls or jumpers over plain trousers. But no one gave any hint of what they were doing or why they were here, and although he was burning to ask, Vic remembered the fearsome declaration of confidentiality he’d been required to sign, in triplicate. Any breach might result in a prison sentence of up to seven years.

After a flurry of introductions the conversation turned to everyday matters: the weather forecast, the temperature of the sea – he gathered with some alarm that some of them enjoyed immersing themselves in it when the tides were right – and what the cooks were boiling up for supper.

‘Saw some veggies and a side of lamb going in the kitchen door this afternoon,’ one said.

‘Sounds promising.’

‘Don’t matter what they start with, they’ll destroy it. We’ll end up with the same bland mush as usual,’ Frank muttered.

‘Don’t listen to Eeyore here. The food’s not that bad.’

‘I haven’t eaten since breakfast,’ Vic admitted. ‘I’m so hungry I could probably eat a donkey.’

‘You might have to.’

‘Where do you come from, Mackensie?’ Frank asked.

‘I’ve just travelled from Cambridge today.’

‘I mean, where do you really come from?’

‘I was born in India, but my father is British, and I have been here since I was eight.’ It was his usual answer, and he steeled himself for what usually came next. Answering would be painful, but at least it usually stopped the interrogation.

‘Is your mother Indian, then?’

‘Was. She died four years ago.’

There was a murmur of sympathy around the table. ‘So sorry to hear that, old chap,’ Johnnie said.

He was saved from further questions by the arrival of Robert Watson-Watt. All, to a man, pushed back their chairs and stood in deference. Vic was struck once more by his powerful presence: the genial air, the breezy smile and apparent informality of his bearing clearly concealing a strong sense of purpose. An impatient man, certainly, and nothing about him would happen by chance.

‘Sit down, for heaven’s sake, there’s no need for all that, chaps. Good cake?’

Frank – who seemed to be the leader in most things – offered to go for more.

‘Och, don’t be bothering them. They brought some to my office earlier,’ he said. ‘Now, where’s my new fellow?’ He glanced around. ‘Ah, there you are, Mr Mackensie. Found us all right?’

‘Yes, I did, sir, with Frank’s help.’