Then, to Denbigh's intense relief, the officers went along the passage. Once again he had been lucky.
Reassured he switched on the light. The cabin was bare of furniture. In one corner lay a pile of books and a couple of sea-stained portmanteaux. Hanging from a coat-hook was an officer's sword-belt. It was mildewed; the stitching of the holster had burst, the buckle was green with verdigris. Attached to the belt was a small, circular leather case secured by a strap.
Denbigh handled it gingerly. There was something hard inside. Curiosity prompted him to unbuckle the strap and open the case. Within was a pocket-compass. What was more, it was a spirit one and seemingly in good order. Without compunction the sub abstracted the compass and slipped it into his pocket.
As he did so he was startled to hear a deep groan. It seemed to sound close to his ear. He wheeled abruptly and shot a glance in the direction of one of the bunks, thinking that he had made a mistake in deeming it untenanted.
There was no one there. Again the groan was repeated. This time the sound seemed to come from the adjoining cabin—the one occupied by Pat O'Hara.
A hole in the bulkhead attracted Denbigh's notice. It was the aperture drilled by the Germans when they made their ineffectual attempt to chloroform the three British officers.
Through it Denbigh could see but a very small portion of the next cabin, but sufficient to observe O'Hara lying on his back in his bunk. He was writhing and groaning. His eyes were wide open and rolling in a horrifying manner.
Outside all was quiet once more.
"I say, old man," whispered Denbigh. "What's wrong?"
At the sound of his voice O'Hara raised himself. He tried to speak, but could not. With an effort he rolled out of his bunk and stood clinging to the edge for support.