od back. Kemp
pushed the striker button and the torch flared. "Watch your eyes," he
warned. The Planeteers reached for belt controls and turned the rheostats
that darkened the clear bubbles electronically. Kemp adjusted his flame
until it was blue-white, a knife of fire brighter by far than the light
of the sun at this distance.

Koa stepped behind Kemp and leaned against his back, because the flame of
the torch was like an exhaust, driving Kemp backward. Kemp bent down, and
the torch sliced into the metal of the asteroid like a hot knife into
ice. The metal splintered a little as the heat raised it instantly from
almost absolute zero to many thousands of degrees.

When the circle was completed, Kemp adjusted his torch again, and the
flame lengthened. He moved inside the circle and cut at an angle toward
the perimeter. His control was quick and certain. In a moment he stood
aside, and Koa lifted out a perfect ring of thorium. It varied from a
knife edge on the inner side to eighteen inches on the outer side.

In the middle of the circle there was now a cone of metal. Kemp cut
around it, the torch angling toward the center. A piece shaped like
two cones set base to base came free. Since the metal cooled in the
bitter chill of space almost as fast as Kemp could cut it, there was no
heat to worry about.

Alternately cutting from the outside and the center of the hole, Kemp
worked his way downward until his head was below ground level. Rip
called a halt. Kemp gave a little jump and floated straight upward. Koa
caught him and swung him to one side. Rip stepped into the hole, and
Santos gave him a slight push to send him to the bottom. Rip knelt and
sighted upward. Kemp had done a good job. The star Rip had chosen as a
guide was straight overhead.

He bounced out of the hole, and, as Koa caught him, he told Kemp to go
ahead. "Dominico, here's your chance. Get tools and wire. Find a timer
and connect up the ten-kiloton bomb. Nunez, bring it here while Dominico
gets what he needs."

Kemp was burning his way into the asteroid at a good rate. Every few
moments he pushed another circle or spindle of thorium out of the hole.
Rip directed some of the men to carry them away, to the other side of the
asteroid. He didn't want chunks of thorium flying around from the blast.

The sergeant major had a sudden thought. He cut off his communicator,
motioned to Rip to do the same, then put his helmet against Rip's for
direct communica