flashed upon the plate and
Costigan's voice greeted them from the speaker.

"Hello, fellows, welcome to our city! Where are you?"

"We don't know," Cleveland snapped back, "and we don't know where you
are, either. Can't figure anything without data. I see you're still
breathing air. Where are the Nevians? How much time we got yet?"

"Not enough, I'm afraid. By the looks of things they will be within
range of us in a couple of hours, and you're so far away yet that it
took our voices four minutes and about fifty seconds to make the round
trip, _on the ultra_! Play that on your calculator, Lyman! You haven't
even touched our detector screen yet. I'm mighty glad to have seen you
fellows again, though, anyway."

"A couple of hours!" In his relief Cleveland almost shouted the words.
"That's time to burn. We can be clear out of the Galaxy in less
than...." He broke off at a yell from Rodebush.

"Broadcast, Conway, broadcast!" that worthy had cried, as Costigan's
image had disappeared utterly from his plate.

Now he cut off the _Boise_'s power, stopping her instantaneously in
mid-space, but the connection had been broken. Costigan could not
possibly have heard the orders to change his beam signal to a broadcast,
so that they could pick it up; nor would it have done any good if he had
heard and had obeyed. So immeasurably great had been their velocity that
they had flashed past the speedster without seeing it, even upon the
ultra-plates, and now they were unknown billions of miles beyond the
fugitives they had come so far to help--far beyond the range of any
possible broadcast. But Cleveland had understood instantly what had
happened. He now had a little data upon which to work, and his fingers
were flying over the keys of the calculator.

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

Then 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," Rodebush applauded. "So close that we can't
use the neutralizers to catch him. If we use a dyne of driving force
we'll overshoot him a million kilometers before I can snap the switches
out."

"And yet he's so far away and going so fast that if we keep our inertia
on it'll t