When the Roughnecks pick up a distress call from pilots Ibanez and Barcalow, who are under attack at a research outpost, Rico risks the safety of his own squad to save Carmen.

Arriving on the planet of Tophet, the Roughnecks are surprised to meet an advanced indigenous species. They claim the bugs came, but couldn't adapt to their climate and died... But where are all the corpses then?

The Valley Forge is enroute to their next campaign, a long trip. The Roughnecks drew the watch as most of the ship's crew is in stasis. Doc is suddenly attacked by Zander who has mutated into a new form of Bug. Zander escapes and runs amok in the ship, letting samples of other Bug types free to keep the Roughnecks busy whilst it heads for the bridge. There it captures Carmen and the Commander and, to stop the Roughnecks from interfering, kills power to the stasis tubes. Gossard manages to restore power to the tubes whilst Rico and Brutto go outside the Valley Forge to the emergency air lock on the bridge. As they enter the Sander Bug notices them and closes the door trapping Brutto in the process and damaging his legs. The rest of the team arrive and Zander escapes in a life-pod to the planet he was trying to crash the Valley Forge onto. Carmen manages to avoid the crash causing the Commander to withdraw earlier comments about automated pilots. The planet is t