A woman being terrorized by a stalker hires and develops a relationship with a handsome private detective, not realizing he'd become her deadly avenging angel.

Paul Harris works at a small research facility on the outskirts of Boston. After a weekend tryst with a co-worker leaves him wanting more, his unreciprocated desires gradually mold into an acute infatuation. When Danielle takes interest in a new scientist at the laboratory, Paul's suppressed resentments and perverse delusions finally become unhinged, triggering a horrific course of events that mercilessly engulf a tortured past and fugitive present.