As The Heart of Valoropens, Torin has been promoted from Staff Sergeant to Gunnery Sergeant and assigned to give briefings on the Silsviss at the Confederation’s Ventris space station. (Big Yellow is still classified Top Secret.) After several weeks of repetitious briefings, Torin is bored stiff, so she jumps at the chance to take charge of a platoon of 32 recruits to the Marines’ training planet Crucible for a rugged winter combat simulation testing. They have hardly begun before they are cut off from off-planet communication and the automated tanks, aerial drones, and other military equipment that is supposed to give them a grueling but non-lethal testing starts trying to kill them for real. The novel is mostly hard-boiled military action as Torin tries to keep her recruits, with the biological needs of three different species, alive long enough to turn them into a smoothly-operating platoon of real Marines; and find out who has reprogrammed the simulation to kill them all.
