d his
luck in being one of the people most familiar with the entire
structure of the ship. It would be unlikely that enemies operating
aboard would think to cut off the air and water passages, or even keep
them under surveillance. Nevertheless, he would be cautious.

He must now get to the machine shop, and enter it without triggering
any more of those--he laughed quietly to himself--Security servos.

The particular tank he was in he had selected carefully. Of the
twenty-one possible combinations, this one he knew would bring him
into the water under the north hall that circled the outer rim.

In a few strides he reached the three-foot-diameter spoke tube through
which the flood of water would pour during a draw-in action such as
that they had had during the flare; let himself over the side head
first, let go and began falling down the seventy-nine foot length of
the tube, accelerated by the light pseudo-gravity of the spin. Even
so, he spread his legs and arms against the walls of the tube to act
as a brake, so as not to arrive with too much impact at the bottom of
the tube.

As he hit the water at the bottom, the tube swung around the
circumference of the rim to the point at its far side at which it
entered its particular river.

The course of his dive carried Mike to the bottom of the curve, and he
started crawling up its far side to where the tunnel entered the
rim-river. There the motion of the fluorescent-lighted water caught
him, and he was swirled quickly to his target, twenty-five feet along,
inspection plate B-36. He grabbed the hand-hold by the plate before he
swirled past, loosened the plate, lifted it only enough to be sure
that the room was empty, and then pushed it off, pulled himself
through, and emerged into the whining dimness of Compressor Room 9,
next to the machine shop. The low whine assaulting his ears was that
created by the air compressors that fed the jets that drove the waters
through the rim.

Stepping over to the wall locker, Mike took out a dry pair of shorts,
a T-shirt, and moccasins, kept there for the purpose of making changes
after such swimming inspections of the rim tanks.

* * * * *

Before entering the machine shop, Mike spotted the Security man
through the open bulkhead--just standing there while Paul and Tombu
grimly worked on; and Millie sat idle, watching.

Mike entered the machine shop casually, as though intent on business,
brushed pa