When wildlife photographer Tara returns home from a photo trip to the California mountains, she's beset by violent agoraphobia. Her boyfriend Matthew tries to get her into treatment as she escalates episodes of self-harm, convincing herself that her house has become home to a dark insect brood.
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".