"Hello," I said with a smile. "I hope you won't mind my company for a while."

"I'm not likely to go for a stroll in—Captain Schnell! Don't—"

Seven and one-half tons of finely wrought and polished tool-steel alloy swung on delicately balanced hinges, coming to rest with the metal-to-metal sound of machined surfaces sliding into a perfect fit with its precision-matched receptacle. Its piston-fit made a pressure on our eardrums. Then the automatic switches took over and motors whirred in solid muffled harmony as the massive bars slid out of their nests into the polished slots.

The ponderous operation that sealed the two of us off from the outside world behind a barrier of drill-proof and burglar-proof and blast-proof solidity concluded not with the mechanical fanfare it deserved, but with a gentle little click that was as final as the Word of God.

"—do that!" gasped Florence Wood, weakly finishing her admonition.

She stared at me.

The knowledge that this bank vault door was equipped with a time-lock that would not permit it to be opened except in the interval between nine-fifteen and nine-thirty in the morning of any working weekday ceased to be mere information and became vitally important to Florence Wood.

So did the secondary knowledge that the bank vault was also contrived in available volume to limit the breathable air. There was not enough to support the average human adult overnight until opening time tomorrow morning. Now there were two of them entombed in it—and she was one of them!

"We'll die!" she screamed.

"Trust me, Florence?"