ed the Chief, a dozen miles away and burning his steering
rockets to close, again. The Chief had the hang of it, now. He didn't
try to steer. He drove toward Joe.

But nothing happened. And nothing happened. And nothing happened. The
two tiny space wagons were 90 miles from the Platform, which was now
merely a glittering speck, hardly brighter than the brightest stars.

There was a flare of light to Earthward. It was brighter than the sun.
The light vanished.

Brown's voice came in the headphones, "_Our missile went off 200 miles
short! He sent an interceptor to set it off!_"

"Then he's dangerous," said Joe. "There'll be war rockets coming up any
second now for him to control from right at hand. We won't be fighting
rockets controlled from 4,000 miles away! They've found proximity fuses
don't work, so he's going to work in close. Give us our course and data,
quick! The Chief and I have got to try to smash things!"

The two tiny space wagons--like stick-insects in form, absurdly painted
a brilliant red--seemed inordinately lonely. It was hardly possible to
pick out the Platform with the naked eyes. The Earth was thousands of
miles below. Joe and the Chief, in space suits, rode tiny metal
frameworks in an emptiness more vast, more lonely, more terrible than
either could have imagined.

Then the war rockets started up. There were eight of them. They came out
to do murder at ten gravities acceleration.

9

But even at ten gravities' drive it takes time to travel 4,000 miles. At
three, and coasting a great deal of the way, it takes much longer. The
Platform circled Earth in four hours and a little more. Anything
intending interception and rising straight up needed to start skyward
long before the Platform was overhead. A three-g rocket would start
while the Platform was still below the western horizon from its
launching-spot. Especially if it planned to coast part of its
journey--and a three-gravity rocket would have to coast most of the way.

So there was time. Coasting, the rising manned rocket would be losing
speed. If it planned to go no higher than the Platform's orbit, its
upward velocity would be zero there. If it were intercepted 500 miles
down, it would be rising at an almost leisurely rate, and Joe and the
Chief could check their Earthward plunge and match its rising rate.

This they did. But what they couldn't do was match its orbital velocity,
which was zero. They had the Platform's eastward s