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.
The bugs have tunnels underneath San Francisco. Military Intelligence wants to blow up the city to get the bugs, but that would also kill all the civilians in the area. The Roughnecks and Walker's Team come up with an alternate plan to deal with the bugs. The city will be saved, but one will pay the ultimate price.
With no LT the Roughnecks are to be disbanded. Before they break up, they fulfill the last request of their C.O. SGT Brutto and General Redwing pay their respects as well. They come across some bugs, Redwing and Higgins are captured. Outnumbered and unable to call for support, the Roughnecks must mount a rescue and destroy the bugs.
The Roughnecks are assigned to protect Oahu. They get 2 new members to their squad. Max Brutto, SGT Brutto's son, and SGT Zimm. Rico's not sure about his abilities as a leader. Soon he'll learn how his former C.O. had a bigger hand in his life than he realized.