Li Ziwei, a bike courier who finds himself at a murder scene, attempts to flee but is dragged off a bridge by the perpetrators. Due to his amnesia caused by his head injuries, he is unable to recognize his adversaries, who have framed him for the crime. Now, armed only with the parcel that contains his only clue and assisted by spunky hitchhiker Tong Xin, Li Ziwei must dodge assassins and cops while trying to clear his name in connection with the mystery murder.