and kept on decreasing it at such a rate
that the heptagon still crept up, foot by foot.

"Hey what's the big idea?" Stevens demanded.

"Coax 'em along. If we run away from them they'll probably reverse power
and go back home, won't they? Their beam is falling apart fast, but
they're still getting so much stuff along it that we couldn't do a thing
to stop them. If they think that we're losing power even faster than
they are, though, they'll keep after us until their beam's so thin that
they'll just be able to stop on it. Then they'll reverse or else go onto
their accumulators--reverse, probably, since they'll be a long ways from
home by that time. We'll reverse, too, and keep just out of range. Then,
when we both have stopped and are about to start back, their beam will
be at its minimum and we'll go to work on 'em--foot, horse, and marines.
Nobody can run us as ragged as they've been doing and get away with it
as long as I'm conscious and stand a chance in the world of hanging one
onto their chins in retaliation. I've got a hunch. If it works, we can
take those birds alone, and take 'em so they'll _stay_ took. We might as
well break up--this is going to be an ordinary job of piloting for a few
days, I think. I'm going up and work with the Martians on that hunch.
You fellows work out any ideas you want to. Watch 'em close, Mac. Keep
kidding 'em along, but don't let them get close enough to puncture us."

* * * * *

Everything worked out practically as Brandon had foretold, and a few
days later, their acceleration somewhat less than terrestrial gravity,
he called another meeting in the control room. He came in grinning from
ear to ear, accompanied by the two Martians, and seated himself at his
complex power panel.

"Now watch the professor closely, gentlemen," he invited. "He is going
to cut that beam."

"But you can't," protested Pyraz Amonar.

"I know you can't, ordinarily, when a beam is tight and solid. But
that beam's as loose as ashes right now. I told you I had a hunch, and
Alcantro and Fedanzo worked out the right answer for me. If I can cut
it, Quince, and if their screens go down for a minute, shoot your
visiray into them and see what you can see."

"All x. How much power are you going to draw?"

"Plenty--it figures a little better than four hundred thousand
kilofranks. I'll draw it all from the accumulators, so as not to
disturb you fellows on the cosmic intake. We don