With no more compunction than if he were shooting a rat, the lieutenant pressed the trigger.

The report of the rifle was outvoiced by a loud detonation, accompanied by a vivid flash. For one moment Terence stood stock still, his eyes temporarily blinded by the sudden glare. Then he realized that his cap had gone. His face was wet, not with the chilly rain but with a warm moisture. Something had struck him on the cheek, inflicting a small cut from which the blood flowed freely.

"A pretty rumpus!" he soliloquized. "The rotter has plugged me—no, it can't be that. It's only a slight gash. I wonder if he hurled a bomb."

"Blowed to atoms, sir; that's what's happened to him—the blighter!" exclaimed a voice that seemed to come from the ground.

"I thought you were a dead man, by Jove!" exclaimed Terence bluntly, as he recognized the sentry by his voice.

"Not yet, sir," replied the man. "He put a bullet through my leg—just above the knee. It don't hurt much, but it kippered me, so I thought I'd lie low and see what happened. I'd a cartridge ready, though, in case of an accident."

"We ought to stop the next train," said Terence, as he stooped to recover his cap. "The rail might be damaged. I think that fellow had a few detonators on him, and my shot did the trick. How did you stop the train I was in?"

"Had a lantern, sir. It's somewhere along the line. But our chaps must have heard the racket, an the sergeant'll be coming along in half a tick."

"Wind the wrong way," declared Terence laconically. "I'll bandage that leg of yours and then I'll get the lantern."

The miscreant's bullet—from a small calibre high velocity pistol—had passed completely through the soldier's leg, fortunately without severing any arteries. Having attended to the wound and bidden the man sit down by the side of the bank, Aubyn set out on his search.