After the events of Invasion, Johnny Rico has been demoted to the rank of colonel and relocated to a Martian satellite to train a new batch of troopers. Unfortunately, these troopers are some of the worst low-performing Rico has ever trained as Mars overall has low support for the war, seeing their planet unaffected by the bug conflict and even suggesting pulling out from the war. Because of their laid back attitude, the denizens of Mars weren’t ready when the bugs attacked. Unknown to everyone, Sky Marshall Amy Snapp executes her plans for power.
Snapp hatched her own plans to destroy Mars while gaining popular support for doing it. She’s well aware of the bug nest growing under Mars for some time, but she decided to take advantage of the bug attack to gain social and political support to scuttle the whole planet. She staged a fleet attack run on the Arachnid Quarantine Zone (AQZ) as a massive distraction. While no one notices, she plans to capture General Carl Jenkins, then fabricate a story in which the Federation was too distracted in the AQZ to save Mars and had to detonate a Q-Bomb (planet destroyer) to cleanse the bug threat and Carl will be blamed for the loss of Mars. Unfortunately, nothing went according to plan.
During the bug attack, Rico and his team survived the initial assault and managed to land on Mars surface. While the bulk of the Federation started their attack run on the AQZ, Snapp captured Carl and disrupted all communications between Earth and Mars. However, Carl telepathically reached out to Carmen Ibanez to come back to Mars before he was captured. Because Carmen and Carl are trusted friends, Carmen redirected her ship back to Mars. Meanwhile, during a bug attack, Rico’s troopers was found by a rescue drop ship and everyone made it on board except for Rico. His boosters ran out of fuel and he fell back into the battlefield and was presumed dead from the bug attack. The surviving team flew away while Rico survived his assault. When awakened, Rico sees his dead lover, Dizzy Flores, to ask him to help stop the Q-Bomb. Unknown to Rico, Dizzy is a telepathic aberration of Carl. While being beaten and drugged by Snapp, Carl managed to telepathically motivate Rico to help stop the Q-Bomb. All was unraveled when Snapp publicly announced the fall of Mars.
Rico’s surviving troopers realized he’s not dead, they returned to save him. Once reunited with his squad, the team heads towards the weather control tower and intend to overload the tower to make it into one massive explosive device that will destroy the bulk of the bug infestation. It was while Snapp was about to destroy Mars that Rico’s squad dismantled the bomb, affecting her approval rating. Now that the Federation Net is back online, the public can see Rico and his team attempting to save Mars, shifting public support away from Amy. With the bomb neutralized and the tower overloading, Carmen arrived with a drop ship and rescued Rico’s surviving team. As soon as they evacuated, the tower detonated like a nuclear device and wiped out all neighboring bugs.
In the aftermath, Carl broke free from his captors and he later returned to power. For his efforts, Rico was reinstated as general to cleanse the bug threat in Mars. As for Snapp, Carl had her quietly arrested and her fate unknown while Rico arranged Snapp’s secret plot to be released to the public; it destroyed Amy’s popularity and public trust because of her corruption. Now that his team is seasoned from battle, Rico congratulated for their hard work and aim to retake Mars.