Video game designer Allegra Geller (Jennifer Jason Leigh) has created a virtual reality game called eXistenZ. After a crazed fan attempts to kill her, Allegra goes on the run with Ted (Jude Law), a young businessman who falls into the role of bodyguard. In an attempt to save her game, Allegra implants into Ted's body the video game pod that carries a damaged copy of eXistenZ. Allegra and Ted engage in a series of experiences that blur the lines between fantasy and reality.