“Hey!  I’ve picked up the trail!  I can’t see it nearby, but it seems to start, thin, about fifty miles up and go on away from there!  That rocket shouldn’t ha’ gone more than twenty miles!  What happened?”

“Watch for the microwave signals,” said Jones’ voice in Cochrane’s headphones.

The voice from the observatory squeaked suddenly.  This was not one of the highly-placed astronomers, but part of the mechanical staff who’d been willing to do an unreasonable chore for pay.

“Here’s the blip!  It’s crazy!  Nothing can go that fast!”

And then in the phones there came the relayed signal of the auto-beacon in the vanished rocket.  The signal-sound was that of a radar pulse, beginning at low pitch and rising three octaves in the tenth of a second.  At middle C—­the middle of the range of a piano—­there was a momentary spurt of extra volume.  But in the relayed signal that louder instant had dropped four tones.  Cochrane said crisply: 

“Jones, what speed would that be?”

“It’d take a slide-rule to figure it,” said Jones’ voice, very calmly, “but it’s faster than anything ever went before.”

Cochrane waited for the next beep.  It did not come in ten seconds.  It was easily fifteen.  Even he could figure out what that meant!  A signal-source that stretched ten seconds of interval at source to fifteen at reception ...

The voice from the observatory wailed: 

“It’s crazy!  It can’t be going like that!”

They waited.  Fifteen seconds more.  Sixteen.  Eighteen.  Twenty.  The beep sounded.  The spurt of sound had dropped a full octave.  The signal-rocket, traveling normally, might have attained a maximum velocity of some two thousand feet per second.  It was now moving at a speed which was an appreciably large fraction of the speed of light.  Which was starkly impossible.  It simply happened to be true.

They heard the signal once more.  The observatory’s multiple-receptor receiver had been stepped up to maximum amplification.  The signal was distinct, but very faint indeed.  And the rocket was then traveling—­so it was later computed—­at seven-eighths of the speed of light.  Between the flat cone on the front of the distress-torpedo, and the flat cone on the ground, a field of force existed.  The field was not on the back surface of the torpedo’s cone, but before the front surface.  It went back to the moon from there, so all the torpedo and its batteries were in the columnar stressed space.  And an amount of rocket-push that should have sent the four-foot torpedo maybe twenty miles during its period of burning, had actually extended its flight to more than thirty-seven hundred miles before the red sparks were too far separated to be traced any farther, and by then had kicked the torpedo up impossibly close to light-speed.