Episode 26: "Metamorphosis" Klendathu: Day 1
Aboard the Valley Forge on a long trip to their next campaign, the Roughnecks have drawn watch as most of the ship's crew rests in suspended animation. While doing a routine check on the stasis tubes, Doc is attacked by Zander who bursts out of his stasis tube, having evolved into a hideous half-bug, half-human creature. The Zander Bug eventually takes over the ship, and to keep the Roughnecks busy, shuts down the power to the crew's stasis tubes. If the power is not restored quickly, the entire crew in suspended animation will perish. Eventually the Roughnecks are able to thwart Zander's plans to crash the Valley Forge on to a mysterious planet but Brutto is severely injured and will be sent to Earth to recoup. Unfortunately, Zander Bug escapes to the planet surface below, which turns out to be the Bug home world of Klendathu.
Episode 27: "D-Day" Klendathu: Day 4
As the squad prepares for the D-Day invasion of the bug home planet of Klendathu, Dizzy receives an official notice from SICON that her brother, Eddie is presumed dead. The news deeply effects the normally gungho Trooper, causing her to become skittish in battle. Unfortunately, the orders come down for the invasion to begin. Dizzy's hesitation concerns Rico (who has just been promoted to Sergeant) and he must determine if she is still fit to be a part of the Roughnecks. Eventually inspired by the fierce determination and never-say-die attitude of a Zulu Squad Trooper, Dizzy regains her confidence in time to save the Roughnecks and help them achieve their mission.
Episode 28: "The Mission" Klendathu: Day 34
While at a temporary camp on Klendathu, the Roughnecks are attacked by a new and dangerous form of arachnid, an Imposter Bug that approximates the size and shape of a human. Able to fit inside stolen power suits, the Imposter Bugs represent a terrible threat to the security of Troopers everywhere. After the attack, the Roughnecks are ordered to rescue the crew of a downed transport ship. Upon arriving at the ship's crash site the squad discovers that the crew have been taken hostage by the Bugs. Even more disturbing is that the Zander Bug appears to be the mastermind behind the kidnapping. The Roughnecks are ordered to retrieve the hostages and terminate the Zander Bug. They track down Zander Bug to his own Bug mound and find that he is using the captured Troopers DNA to create ever evolving generations of Imposter Bugs. In the end, Dizzy inspires Zander Bug to remember his humanity and he attacks his own Bugs, allowing the Roughnecks to escape to safety.
Episode 29: "Letters Home" Klendathu: Day 134
The Roughnecks are facing a "Battle of the Bulge" situation on the Bug home planet of Klendathu. They have been ordered to hold the line against an inevitable (and overwhelming) Bug siege. The odds of surviving are not in their favor. Throughout the night, Higgins winds up taping a series of heartfelt "goodbyes" from each of the Troopers to their various loved ones. When day break comes, the Troopers are able to hold off the Bug horde long enough to be saved by massive air strike, but the "goodbyes" leave a lasting impression on them all.
Episode 30: "Checkmate" Klendathu: Day 181
After a long day of battling Bugs, the Roughnecks are called to a mission briefing only to find themselves in the presence of Sky Marshall Sanchez himself. The Sky Marshall confirms the existence of the Bug Queen and assigns Alpha Squad (along with rival Echo Squad) the difficult task of finding and exterminating her. Carl is reassigned to the Roughnecks to aid in the mission, but the squad finds him distant and cold, but with heightened psychic abilities. The Roughnecks are able to fight their way into the Bug Queen's lair only to allow her escape. Unfortunately, she's on her way to Earth.
During this campaign the Queen, Royal Centurions, Royal Guard, the Imposter Bug, Rhino Bugs, Nurses, and Workers are encountered by the Roughnecks for the first time.