The distant future does not look too rosy for humanity. There are completely different social norms, only those who have served in the Federal service are full citizens. In addition, the very existence of humanity is threatened by the attacks of alien bugs, which occupy planets in space and are beginning to threaten the Earth. High school student Johnny Rico signs up for the service over his wealthy parents' objections and is assigned to the infantry. His crush, the attractive Carmen, wants to become a pilot and his friend Carl is recruited for military research. Together with Rico, the sympathetic Dizzy joins the infantry and falls in love with the young man. Although the others see him as a slick kid from a wealthy family, Rico slowly toughens up in the extremely tough training. He is sent with his unit to the planet Klendathu, where he finds himself in the midst of battle for the first time. The battle ends in disaster, however, when the bugs slaughter a hundred thousand people in a single hour. Rico is badly wounded. After recovering, he is assigned to a unit commanded by his former teacher Jean Rasczak. Rico and his friends still face an almost hopeless battle against multiple odds.
