Larry’s burst of temper cooled down. He was in perfect possession of himself when next he spoke. “I’m going to call your bluff, Labar. I’m going to see if your people have blocked every way out. You’d better hope for your own sake that they haven’t. Come on Tom⁠—and you Billy. The rest of you keep an eye on this man.”

He crept away accompanied by the two men he had designated farther along the tunnel. By straining his ears Labar heard another steel door creak back. Apparently the tunnel towards its seaward end was also guarded.

Larry and his two companions guided by the gleam of an electric torch moved swiftly along the damp tunnel. The leader was thoughtful.

“Billy,” he said, “I’m not sure that we haven’t overplayed our hand. If that fellow’s telling the truth we’re booked for trouble.”

“I begin to wish we hadn’t snaffled him,” said Billy. “He might not have run across that panel. If he’d overlooked it we were OK. We’d simply have had to wait till they made up their minds we had cleared off.”