tandby light quivered
hysterically from bright to dim and back again. The rate of quivering
was fast. It was very nearly a sine-wave modulation of the light--and
when a Mahon-modified machine goes into sine-wave flicker, it is the
same as Cheyne-Stokes breathing in a human.

He plunged forward. He jerked open Betsy's adjustment-cover and fairly
yelped his dismay. He reached in and swiftly completed corrective
changes of amplification and scanning voltages. He balanced a capacity
bridge. He soothed a saw-tooth resonator. He seemed to know by sheer
intuition what was needed to be done.

After a moment or two the standby lamp wavered slowly from
near-extinction to half-brightness, and then to full brightness and
back again. It was completely unrhythmic and very close to normal.

"Who done this?" demanded the sergeant furiously. "He had Betsy close to
fatigue collapse! He'd ought to be court-martialed!"

He was too angry to notice the three civilians in the room with the
colonel and the lieutenant who'd summoned him. The young officer looked
uncomfortable, but the colonel said authoritatively:

"Never mind that, Sergeant. Your Betsy was receiving something. It
wasn't clear. You had not reported, as ordered, so an attempt was made
to clarify the signals."

"Okay, Colonel!" said Sergeant Bellews bitterly. "You got the right to
spoil machines! But if you want them to work right you got to treat 'em
right!"

"Just so," said the colonel. "Meanwhile--this is Doctor Howell, Doctor
Graves, and Doctor Lecky. Sergeant Bellews, gentlemen. Sergeant, these
are not MDs. They've been sent by the Pentagon to work on Betsy."

* * * * *

"Betsy don't need workin' on!" said Sergeant Bellews belligerently.
"She's a good, reliable, experienced machine! If she's handled right,
she'll do better work than any machine I know!"

"Granted," said the colonel. "She's doing work now that no other machine
seems able to do--drawing scrambled broadcasts from somewhere that can
only be guessed at. They've been unscrambled and these gentlemen have
come to get the data on Betsy. I'm sure you'll cooperate."

"What kinda data do they want?" demanded Bellews. "I can answer most
questions about Betsy!"

"Which," the colonel told him, "is why I sent for you. These gentlemen
have the top scientific brains in the country, Sergeant. Answer their
questions about Betsy and I think some very high brass will be grateful.

"B