entire operation, neither man spoke and on shore, the
listeners could hear only the heavy breathing of the pair and an
occasional muffled sound of a clamp going into place.

When the plastic was locked down, Troy carefully unclipped a timer
fused from his belt and handed it across. He spoke for the first time
since they left the tractor. "It's set for seven minutes." In the
wavering light of the murky waters, he saw Alec glance up at him and
then gingerly insert the fuse into the explosive.

"Get moving," Alec ordered. Troy started inching his way back along the
pump housing wall. Alec waited until Troy moved into the gloom and almost
out of sight, then flipped the water-tight switch that activated the fuse.
The device was armed. In seven minutes, if the pile didn't go critical
before then, the charge would detonate--whether they were back on the
surface or not.

He shoved himself free of the pile housing and followed Troy back
along the wall of the base. At the hull of the tractor, he made the
foot-at-a-time crossover and again fought suit and current to get back
to the cab. The seconds ticked off into the first minute and into the
second. Ahead, Troy had reached the aperture of the cab door and
reached in to grasp the end of the steel safety belt. He hauled
himself into the seat and looked back for Alec.

The other engineer had just reached the cab. He swung a leg over the
sill and at that moment, a surge of current whipped his suit. He
twisted, grabbed for a handhold and missed and shot up towards the
surface. In that same instant, Troy shot up out of the seat, holding
the end of the belt in one hand and grabbing for Alec's ankle with
the other. He caught it and clutched. "Up, fast," he screamed.

The tractor snapped up under them and threw both men against the seat.
Alec seized a control handle and hauled himself into the seat as the
vehicle surged upwards. Under full power, it was whipping towards the
surface and now, the water pressure was holding them down. The timer
passed the four-minute mark when the six-ton carrier burst out of the
water in a geyser of spray. The cable whipped and almost threw them
from the cab. Then there was a spine-snapping side jerk as the Number
One crane operator began smoking the cable pulling them to the shore.

Thirty seconds later the tractor slammed to the ground. Hall and the
crane carrier driver were waiting. They reached in and jerked the two
engineers from the seat and h