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.
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.
The Bug Queen has survived a battle on Klendathu, and is headed for Earth. When the Troopers discover that the bugs have cloned human DNA to be able to take human form, they realize that extermination is going to be even more difficult.
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.