The Roughnecks are ordered to the planet Hydora after a transport bug is seen leaving Pluto. The Roughnecks mission is to establish if Hydora is the bug home world or not. While there they receive an extremely disturbing message.
Rico is reunited with Carmen when a retrieval mission goes wrong. What starts as a minor operation on Hydora develops into a full blown battle as Bug numbers turn out to be far higher than expected.
When a Cyborg named Chas "Cybernetic Humanoid Assault System" is assigned to the Roughnecks, he is befriended by Higgins, who views the robot as a kindred outsider.
Colonel T'Phai the Skinnie who was partially responsible for Carl's fried brain joins the unit just as they're assigned the task of taking Zegema Beach as part of the Tesca Nemerosa campaign.
After Gossard receives a minor injury, Rico is assigned a marauder suit for the Roughneck's next mission: they're heading upriver to capture a Brain Bug.
Rico hovering in a coma between life and death flashes back to High School with Dizzy, Carl, Carmen and Razak, and Basic Training with Drill Sergeant Zim.