War Dogs

by Greg Bear

Venn returns home from his last tour of duty on "The Red" (Mars) and settles into his apartment in [[Seattle, Washington]], remembering the events of that tour:

Venn and his squad's combat drop onto Mars goes badly wrong after their fleet is attacked in orbit by the Antags. Venn and a handful of survivors are forced to trek across the Mars desert, barely surviving from day to day by finding isolated caches of air and water dropped for previous expeditions. They are unable to establish contact with other elements of their force or their commanders, nor can they receive any intel on the enemy's numbers or locations. One ominous sign of the Antags' superior capabilities is when a comet impacts near the horizon, its course apparently directed by the Antags.

Just as they are about to asphyxiate, they are rescued by Teal, a runaway from a settlement of "Muskies", the leftovers of Earth's earlier, ambitious attempts to establish colonies on Mars.