The big gun fired and missed.

Lloyd wondered if he knew the flyer. There were only about five thousand pilots on active service in the UK at any one time. Quite a lot of them had been to Daisy’s parties. Lloyd thought of Hubert St John, a brilliant Cambridge graduate with whom he had been reminiscing about student days a few weeks ago; of Dennis Chaucer, a West Indian from Trinidad who complained bitterly about tasteless English food, especially the mashed potatoes that seemed to be served with every meal; and of Brian Mantel, an amiable Australian he had brought across the Pyrenees on his last trip. The brave man in the Tiffy could easily be someone Lloyd had met.

The anti-aircraft gun fired again, and missed again.

Either the pilot still had not seen the gun, or he felt it could not hit him; for he took no evasive action, but continued to fly dangerously low and wreak carnage on the troop train.

The engine was just a few seconds from the tunnel when the plane was hit.

Flame flared from the plane’s engine, and black smoke billowed. Too late, the pilot veered away from the railway track.

The train entered the tunnel, and the carriages flashed past Lloyd’s position. He saw that every one was packed full with dozens, hundreds of German soldiers.

The Tiffy flew directly at Lloyd. For a moment he thought it would crash where he lay. He was already flat on the ground, but he stupidly put his hands over his head, as if that could protect him.

The Tiffy roared by a hundred feet above him.

Then Legionnaire pressed the plunger of the detonator.

There was a roar like thunder inside the tunnel as the track blew up, followed by a terrible screeching of tortured steel as the train crashed.

At first the carriages full of soldiers continued to flash by, but a second later their charge was arrested. The ends of two linked carriages rose in the air, forming an inverted V. Lloyd heard the men inside screaming. All the carriages came off the rails and tumbled like dropped matchsticks around the dark O of the tunnel’s mouth. Iron crumpled like paper, and broken glass rained on the three saboteurs watching from the top of the embankment. They were in danger of being killed by their own explosion, and without a word they all leaped to their feet and ran.

By the time they had reached a safe distance it was all over. Smoke was billowing out of the tunnel: in the unlikely event that any men in there had survived the crash, they would burn to death.

Lloyd’s plan was a success. Not only had he killed hundreds of enemy troops and wrecked a train, he had also blocked a main railway line. Crashes in tunnels took weeks to clear. He had made it much more difficult for the Germans to reinforce their defences in Normandy.

He was horrified.

He had seen death and destruction in Spain, but nothing like this. And he had caused it.