Tom, a scientist, invents a machine that can insert a person into the subconscious mind of another person. Desperate for funding to complete his prototype, he is forced to accept money from an anonymous investor. When the investor threatens to pull out, Tom reluctantly agrees to a demonstration a month ahead of schedule. The investor turns out to be an official at the Department of Corrections who wants to use the machine to extract involuntary confessions from convicts. Initially repulsed by the idea, Tom's friend, an entrepreneur, convinces him to proceed, and Tom enters the mind of Anthony, an addict who is suspected of having killed his girlfriend Adrienne. Though Anthony volunteers in order to prove his innocence, Tom is able to walk through Anthony's fractured memories and prove his guilt. However, when Tom tries to return his consciousness to his own body, the machine malfunctions and traps him in Anthony's mind. Unable to leave, Tom passes the years by watching Anthony's memories, while his body remains in a coma.