“Looks as if Larry had come back,” said Moreland.

“Or Tom and his pal,” said Labar. “We may have to do some digging out.” He put his face close to the metal and raised his voice. “You inside there. Can you hear me? Be good boys now and come out. You’ll do yourselves no good by this foolishness.”

There was no answer. Labar turned to the prisoner. “Show me how this is supposed to work,” he ordered.

With docility the man indicated an unobtrusive knob at the side of the wall. “Push it in and then turn it first to the right and then to the left.”

The detective obeyed, but still the blank sheet of steel remained unmoved. He fiddled impatiently with the knob and suddenly the slab glided back. In an instant the officers had crouched back to the side of the wall with weapons ready and their torches searching the darkness, half expecting a shower of bullets from the interior.