Agnes is a waitress living in a rundown motel in Oklahoma, trying to escape her troubled past and the threatening presence of her abusive ex-husband, Jerry, who has recently been released from prison. Her life takes a peculiar turn when she meets Peter, a seemingly gentle drifter with a mysterious background. As they form a bond, Peter shares his paranoid beliefs about secret government experiments and surveillance. He reveals to Agnes that he is a former soldier who claims to have been exposed to these experiments, involving bugs that have supposedly infested his body. His theories captivate and terrify Agnes, drawing her deeper into his world.

As their relationship develops in the claustrophobic setting of the motel room, Agnes becomes increasingly influenced by Peter's delusions. The outside threat of Jerry's return exacerbates the sense of isolation and fear. Together, they embark on a disturbing journey fueled by paranoia, leading them to increasingly extreme measures to rid themselves of the imagined infestation. The tension escalates as they barricade themselves against the perceived outside threats, unraveling in a shared psychosis that blurs the lines between reality and delusion. Peter's influence over Agnes becomes all-consuming, challenging her grip on reality as they spiral further into madness.