Nerdy computer specialist Thomas Cross (Edward Furlong) witnesses the murder of his online friend, Cathy (Valerie Decobert), through her webcam. Though Thomas is unaware of her actual name or location, he becomes a suspect when her body is found in Amsterdam. The police do not credit his testimony, but attractive Officer Claire Bligh (Emilia Fox) believes his story. Recruiting the help of experienced hacker Mark (Chiwetel Ejiofor), the trio sets out to find the real killer.