Here was a predicament. It flashed across Labar’s mind that these men were scarcely likely to have submitted to be shut in the tunnel during the absence of those who held the key to their release and at the risk of accident unless they themselves knew the secret. He switched his light off and fired at the floor of the tunnel.

“That will be unlucky for you,” he declared ominously. “If that door isn’t opened in a matter of seconds I’ll shoot my way through it⁠—and you.”

Adèle Gertstein who had never ceased her subdued wailing now gave a sharp cry of terror. And then the door creaked back.