‘And we won’t incur any travel costs,’ Vic added. They got their permission.

Arriving at the flying boat station, they were greeted by a tall, good-looking man. Vic recognised him immediately.

‘Captain Burrows at your service, gentlemen,’ he said, shaking hands with a vice-like grip. ‘The boss says you’ve a piece of kit you’d like testing. How can we help?’

Just being in the pilot’s presence made Vic feel like a schoolboy once more: in his first term at boarding school, watching the sixth-formers with their long limbs and fine physiques, their careless confidence with the teachers, their effortless grace and skill on the tennis courts or the cricket pitch. He was completely overawed.

Johnnie at least had the advantage of age and experience, as well as nearly matching the man in height. But Vic, almost a foot shorter than both of them, dark-haired to their blond, brown-skinned to their fair, felt even more than usual as though he’d landed on an alien planet.

They repaired to a scruffy office at the back of one of the hangars, and Johnnie explained that because of the secret nature of their work it would not be possible to divulge precisely the purpose of their experiment. ‘But we’ll need to attach aerial lines – what we call dipoles – from front to aft, probably somewhere on the upper wing to the tail. We don’t anticipate they will make any difference whatsoever to the handling or fuel consumption of the plane. All we require is a few passes timed to our own equipment at the Manor. We can choose the day to your convenience. And we’ll take your advice on the type of plane you think will be suitable first time around. After that, perhaps we can try a few others.’

The captain listened with an impressive level of attention, asking intelligent questions about the aircraft they might like to use – explaining that he’d been chosen to work with them because he had the widest experience of all types on the station. Within half an hour they found themselves being led out onto a jetty.

From a distance the plane looked like a toy, but as they approached it was clear this was no flimsy biplane like the Swordfish Vic had visited on Empire Day. It had the hull of a destroyer – much of which was submerged below the water line – and two sets of wings spanning what looked like the length of a tennis court. To the underside of the upper set were attached two mighty Rolls Royce engines with propeller blades several yards long.

‘Phew,’ Johnnie whistled. ‘This is a serious piece of kit, Captain Burrows.’ Vic smiled to himself. Their recent airfield visits were often eased by his friend’s canny ability to say the right thing, and it hadn’t taken long to learn that the usual way to a pilot’s heart was to flatter him with admiration for his aeroplane.

The wind was blustery and chill out here on the jetty, the sea choppy. ‘I can’t take you up today. It’s too rough,’ the captain said. ‘But we can go on board if you like?’