Set in the future, the story follows a young soldier named Johnny Rico and his exploits in the Mobile Infantry. Rico's military career progresses from recruit to non-commissioned officer and finally to officer against the backdrop of an interstellar war between mankind and an arachnoid species known as "the Bugs".

A US Army officer, who made a "friendly fire" mistake that was covered up, has been reassigned to a desk job. He is tasked to investigate a female chopper commander's worthiness to be awarded the Medal of Honor. At first all seems in order. But then he begins to notice inconsistencies between the testimonies of the witnesses...