Tom, and
Captain Allison huddled near the torn side of the time capsule. They
could hear Strong talking to Tom.

"There is a vault on every spaceship in the Solar Alliance, Tom," Strong
was explaining. "The vault is locked before blast-off and opened after
landing by a light-key operated only by a trusted spaceport security
officer. This key flashes a series of light vibrations, in sequence,
into the electromagnetic lock on the vault. It's really nothing more
than a highly developed flashlight except that it flashes multiple
combinations of lights, each containing certain electronic vibrations.
The electromagnetic lock can only be opened with the proper combinations
of colors and vibrations flashed by the light-key. Of course each ship
has a different code of colors and vibrations, but the code itself
wouldn't be hard to crack. The big thing would be to have an adjustable
light-key, so that if one combination of colors and light vibrations do
not work, you can try another. In that way you could open any energy
lock on any vault in the system."

"And Wallace and Simms--" Tom hesitated.

"Yes, Corbett," said Strong grimly. "Wallace and Simms stole an
information sound spool from the capsule. On that spool was a detailed
description of the energy lock and the adjustable light-key. There were
only seven keys in the system up to now. If we don't catch Wallace and
Simms, there'll be eight."

"Great galaxy," Commissioner Hawks broke in. "This will ruin the
exposition! The Alliance will close it after--"

Strong waved a calming hand at Hawks. "I've already spoken to Commander
Walters at Space Academy, Mike," he said. "He wants this to remain a
secret. No one knows about it besides us, and no one will. I'm taking
your oaths, your spaceman's word, that it will remain a secret. There's
no use in starting a panic. You'll keep the exposition going as if
nothing had happened."

"But what can the Solar Guard do, sir?" asked Tom.

"We'll start the greatest search the system has ever seen," replied
Strong calmly. "But the order for their arrest will be issued for some
other violation." The Solar Guard officer suddenly noticed Roger for the
first time.

"Oh, Manning!" he said, smiling. "Good to see you. How do you feel?"

"O.K., sir," replied Roger. "But I'd feel a lot better if those space
crawlers didn't have the combination to every safe and vault in the
universe!"

Strong nodded. "This is one of the cleverest crimes in