As a high school student in Buenos Aires, Johnny Rico is uncertain about his future aspirations. However, his childhood friend Carl and romantic interest Carmen opt to participate in the Federal Military, which prompts Johnny to consider enlisting too, with the hope of pursuing Carmen into space. Unbeknownst to him, fate has a different plan; an imminent conflict against an invading extraterrestrial species known for insect-like abilities is brewing in the outer planets, and Johnny quickly adapts from being a civilian to a soldier.