Vitya watched the speckled panorama, crowded tubes intersecting the domes of the habitats. Each blurred pixel a man, woman or child. Any one of them like him, once an ovum delivered to seed the manufactories of a new world. The spectrum of colours became coarse blocks as the ship rotated in high-orbit. Only the yellow dappled surface of the moon in view.

When the image returned with clarity, Vitya gave the order: “Deliver the payload.”

Leaning on the helmsman’s chair, Vitya’s gold-trimmed white uniform glistened. The on-deck cameras recorded everything for posterity. Above each of the command crew, a terminal display fluctuated with mission telemetry. The UESS Calliope locked into a geostationary orbit. Keeping a synchronistic distance from the other destroyers in the group. The first wave bombs locked on to their targets. Power generators and the tethering lines locking orbital platforms to the ground.

The projection displayed a warped expanding brown circle with a black smokey edge.

“Assess impact,” Vitya said. “And begin the second-wave.”

The target profiles changed. Black fields of vegetation blazed in expanding concentric circles of plasma. The oxygen-producing vines evaporated into the sulphur dioxide atmosphere.

The bridge lights turned red. On the display, an icon circled a flash-point on the surface. Some twelve kilometres from the main cluster of domes. The ship’s AI identified a launch, on an escape velocity.

“Could be missiles,” the weapon’s officer Sami said.

“Or colonists trying to make an escape,” Evelyn, the seasoned first officer countered.

“Set course to intercept,” Vitya brought the discussion to an end. “Nobody is leaving Io.” Using an encrypted channel to the other ships, “Continue bombardment, intercepting launch craft.”

The ship’s movement around the planet’s orbit had no impact on the localised gravity of the bridge. In half a minute, the civilian transport was within sight.

“No comms,” Vitya pulled up the mission protocols on the screen for all to see. “Destroy it.”

Sixteen Actaeon missiles arced from the sides of the Calliope. Bright bubbles of bursting nuclear payloads and high-intensity radiation expanding.

The Calliope’s loudspeakers synthesised a warning, “Unidentified projectile on collision trajectory.”

A small conical pod, about two metres long, hit the ship’s hull. Stabilisers steadied the impact. The tail of the Calliope inked with black hexagons. Webbing spread outwards from the point of impact like shattering glass. A gooey spiral consuming the alloyed structure.

“It’s a nanite bomb!” Sami cried.

“Suit up,” Vitya snapped into action.

The crew raced to the forward escape hatch, a shuttle waiting. The black goop clipped forward. The hazard lights went off, systems deactivated.

“It’s leaving the weapon systems intact,” Evelyn said.

Gesturing for her to board the shuttle, Vitya closed the hatch. He sprinted to the starboard engines. The nanite swarm crawled the walls like a gravity-defying oil slick. Cutting a path to the casing of the rocket boosters, he had no final words.

From the shuttle, the crew watched the Calliope fracture, burning up in Io’s atmosphere.