When Ellie (Christina Ricci) and brother Jimmy (Jesse Eisenberg) become involved in a car accident along a stretch of road through the Hollywood Hills, they are attacked by a strange beast and a girl is killed. Jimmy becomes convinced that their attacker was no normal animal, but a werewolf. However Ellie isn't buying it and thinks her brother is simply going through a bout of emotional trauma, caused by the recent loss of their parents. But it soon becomes obvious, through a series of strange events, that Jimmy may have been right, and now, in order to lift the curse, sister and brother must find out who their attacker was and destroy them before it’s too late. Also starring Milo Ventimiglia and Shannon Elizabeth.