lp;
far beyond the range of any possible broadcast. But Cleveland understood
instantly what had happened. He now had a little data upon which to
work, and his hands flew over the keys of the calculator.

"Back blast, at maximum, seventeen seconds!" he directed crisply. "Not
exact, of course, but that will put us close enough so that we can find
'em with our detectors."

For the calculated seventeen seconds the super-ship retraced her path,
at the same awful speed with which she had come so far. The blast
expired and there, plainly limned upon the observation plates, was the
Nevian speedster.

"As a computer, you're good, Cleve," Rodebush applauded. "So close that
we can't use the neutralizers to catch him. If we use one dyne of drive
we'll overshoot a million kilometers before I could snap the switch."

"And yet he's so far away and going so fast that if we keep our inertia
on it'll take all day at full blast to overtake--no, wait a minute--we
could _never_ catch him." Cleveland was puzzled. "What to do? Shunt in a
potentiometer?"

"No, we don't need it." Rodebush turned to the transmitter. "Costigan!
We are going to take hold of you with a very light tractor--a tracer,
really--and whatever you do, DON'T CUT IT, or we can't reach you in
time. It may look like a collision, but it won't be--we'll just touch
you, without even a jar."

"A tractor--inertialess?" Cleveland wondered.

"Sure. Why not?" Rodebush set up the beam at its absolute minimum of
power and threw in the switch.

While hundreds of thousands of miles separated the two vessels and the
attractor was exerting the least effort of which it was capable, yet the
super-ship leaped toward the smaller craft at a pace which covered the
intervening distance in almost no time at all. So rapidly were the
objectives enlarging upon the plates that the automatic focusing devices
could scarcely function rapidly enough to keep them in place. Cleveland
flinched involuntarily and seized his arm-rests in a spasmodic clutch as
he watched this, the first inertialess space-approach; and even
Rodebush, who knew better than anyone else what to expect, held his
breath and swallowed hard at the unbelievable rate at which the two
vessels were rushing together.

And if these two, who had rebuilt the super-ship, could hardly control
themselves, what of the three in the speedster, who knew nothing
whatever of the wonder-craft's potentialities? Clio, staring into the
plate with