In a small New England town, the Brooks family receives devastating news that their son Andy, a soldier, has died in the Vietnam War. However, grief turns to shock when Andy inexplicably returns home the following night, appearing physically unharmed but emotionally distant and detached. His parents, Charles and Christine, are overjoyed yet puzzled by his sudden reappearance. While Andy's old friends and girlfriend try to reconnect with him, they notice he is unusually cold and withdrawn. The world seems foreign to him, and he struggles to adapt to the life he had left behind.

As days go by, Andy’s behavior becomes increasingly erratic and disturbing. His parents, particularly Christine, begin to suspect that Andy is not who he seems to be. He exhibits abnormal traits and a propensity for violence, causing tension and fear within the household. Charles, still overjoyed by his son's return, is in denial, but the ominous atmosphere grows thicker with each passing day. The sense of dread culminates in a series of unsettling events, forcing the Brooks family to confront the terrifying reality about their son’s return.