Bickering couple Zakes (William Ash) and Beth Christine Bottomley) witness a disturbing sight on a moonlit stretch of freeway, and find themselves drawn into a deadly confrontation after disagreeing about how to respond to what they've just seen. The rain falling from the sky as he drives along the M1, Zakes is shocked to see the back of a truck slide open, and a young woman fighting for her life. After phoning the police, Zakes ignores Beth's pleas to tail the truck, instead pulling into the next pit stop. Infuriated, Beth storms off, and vanishes without a trace. Later realizing that his girlfriend has just become the next victim, Zakes speeds to catch up with the truck and finds himself locked in a vicious battle of wills with a relentless killer who seems capable of predicting his every move.