Lieutenant Lloyd Williams arrived by train from Cardiff on a Sunday in April 1940. Carrying a small suitcase, he walked up the hill to Tŷ Gwyn. He had spent eight months training new recruits – the same work he had done in Spain – and coaching the Welsh Rifles boxing team, but the army had at last realized that he spoke fluent German, transferred him to intelligence duties, and sent him on a training course.

Training was all the army had done so far. No British forces had yet fought the enemy in an engagement of any significance. Germany and the USSR had overrun Poland and divided it between them, and the Allied guarantee of Polish independence had proved worthless.

British people called it the Phoney War, and they were impatient for the real thing. Lloyd had no sentimental illusions about warfare – he had heard the piteous voices of dying men begging for water on the battlefields of Spain – but even so he was eager to get started on the final showdown with Fascism.

The army was expecting to send more forces to France, assuming the Germans would invade. It had not happened, and they remained at the ready, but meanwhile, they did a lot of training.

Lloyd’s initiation into the mysteries of military intelligence was to take place in the stately home that had featured in his family’s destiny for so long. The wealthy and noble owners of many such palaces had loaned them to the armed forces, perhaps for fear that otherwise they might be confiscated permanently.

The army had certainly made Tŷ Gwyn look different. There were a dozen olive-drab vehicles parked on the lawn, and their tyres had chewed up the earl’s lush turf. The gracious entrance courtyard, with its curved granite steps, had become a supply dump, and giant cans of baked beans and cooking lard stood in teetering stacks where, formerly, bejewelled women and men in tailcoats had stepped out of their carriages. Lloyd grinned: he liked the levelling effect of war.

Lloyd entered the house. He was greeted by a podgy officer in a creased and stained uniform. ‘Here for the intelligence course, Lieutenant?’

‘Yes, sir. My name is Lloyd Williams.’

‘I’m Major Lowther.’

Lloyd had heard of him. He was the Marquis of Lowther, known to his pals as Lowthie.

Lloyd looked around. The paintings on the walls had been shrouded with huge dust sheets. The ornate carved marble fireplaces had been boxed in with rough planking, leaving only a small space for a grate. The dark old furniture that his mother sometimes mentioned fondly had all disappeared, to be replaced by steel desks and cheap chairs. ‘My goodness, the place looks different,’ he said.

Lowther smiled. ‘You’ve been here before. Do you know the family?’

‘I was up at Cambridge with Boy Fitzherbert. I met the Viscountess there, too, although they weren’t married then. But I suppose they’ve moved out for the duration.’

‘Not entirely. A few rooms have been reserved for their private use. But they don’t bother us at all. So you came here as a guest?’