He opened the communications channel in his small ship. All of his volunteer workers listened in from their own vessels. “My brother died down there on Golgen. So did members of many of your clans. By the Guiding Star, now it’s up to us to do something about it.”

He drew a breath. Jess had not rehearsed his speech. “Roamers are not a violent people. We don’t have an impressive military force or weapons of mass destruction. But we are not to be trifled with. We will resist these enemies and avenge our lost family members. Not one of us can shrink from this task. I certainly don’t intend to.”

Growling oaths and muttered cheers came over the communications link, fierce determination that smothered an undercurrent of fear.

“Lucky for us the universe provides its own weapons,” Jess said. “We’re going to use them.”

The system was surrounded by an arsenal of cometary shards, giant balls of ice that he would convert into bombs. Back on Plumas, he had already analyzed precise mappings of the Kuiper belt, projecting millions of cometary orbits and simulating the results of perturbations. He found more than a thousand candidates, any one of which would rain incredible destruction onto Golgen.

Jess had an intuitive feel for celestial mechanics and orbital maneuvers. He had always been particularly good at navigation and Roamer “stargames,” looking at constellations from different perspectives and backtracking to place the viewer on an objective map of the Spiral Arm. When he was younger, he’d liked to look at the maps, often with Tasia, and imagine different places where he’d never gone, exotic worlds or galactic phenomena that could not be fully appreciated through small images on a screen.

Today, Jess gritted his teeth and stared at Golgen’s celestial cartography for a different purpose entirely. The ponderous and inexorable paths determined by celestial mechanics often took centuries, and he eliminated most of the alternatives, selecting only those comets that could be dropped in steep hyperbolic orbits, massive cannonballs carrying enough kinetic energy for an impact equivalent to a thousand atomic warheads. Eighteen outer comets were viable projectiles.

His Plumas commando crews—everyday water miners, pump specialists, and ice engineers—carried automated reaction thrusters that would dig out and hurl chunks of cometary mass in the opposite direction. When the constant recoil persisted for weeks and weeks, it would gradually perturb the comet out of orbit and send it down on a collision course.

“You all know your targets. Let’s start rolling these big ice bombs down to smack Golgen right in the face.” Jess lowered his voice to a growl. “Those aliens don’t realize just how much trouble they’ve asked for.”