She dropped into the gunner's seat and punched the gun live. Then she heeled up the rocker switch to elevate the muzzle as directed.

Sergeant Jensen was snapping the feed lips of each ammunition drum into the female connector of the drum ahead of it. Rigging them this way increased the chance of malfunction, but neither he nor any of his crewwere going to pop up to feed a fresh can in normal fashion.

"Sarge, I'm ready," said the trainee in a voice raised two octaves by the sonic boom a moment before.

Jensen locked the last can in place and leaped to the gun. Leaning across Herzenberg to get a sight line, he rotated the cannon mount 10° to the right to eyeball it in line with the track down which the starship had disappeared. The gun had electronic sights that would spike a gnat at a kilometer, but at this instant there was neither time nor a hard target for them.

With his right hand, Jensen threw the Continuous Fire toggle. His left hand grasped Trooper Herzenberg by the collar, and he lunged for the shelter. The muzzle blasts of the cannon were so loud that the rain of bombs was a flickering white light, not a sound, to the cowering gun crew.

Warned by the flash, Trooper Iris Powers grabbed her boots and jumped into her shelter. Lieutenant Hussein ben Mehdi was right behind her.

The shelters were half-cylinders, each grown from a single crystal of beryllium. The shelters would not stop a shell or even a bullet at any normal range, but they were generally proof against the tiny splinters spraying from overhead bursts. That was the threat against which foot-soldiers since the Napoleonic Wars had been least able to protect themselves.