colonized, there had never been a single occasion where the sirens had
warned of the failure of the screens. There had been many tests,
especially for the school-age children and the miners working far below
the surface of the satellite, but this was the first time the sirens
howled a real warning of danger and death.

Strong raced back to the control tower of the spaceport in a jet car and
burst into the room where the captain was still asleep on the couch.
Strong shook him violently.

"Wake up, Joe!" he cried. "Come on. Wake up."

"Uh--ahhh? What's the--?" Howard sat up and blinked his eyes. "Steve,
what's going on?"

"The screen at sector twelve has collapsed. How many people are still in
there?"

"Collapsed! Sector twelve?" Howard, still groggy with sleep, dumbly
repeated what Strong had said.

Strong drew back his hand and slapped him across the face. "Come out of
it, Joe!" he barked.

Howard reeled back and then sat up, fully awake.

"What--what did you say?" he stammered.

"Sector twelve has gone," Strong repeated. "How many people are left
there?"