Kiss Me Deadly - Robert Aldrich

Private Investigator Mike Hammer gets involved in a murder case after he gives a lift to Christina Bailey. She is obviously on the run as she is barefoot and wearing nothing but a trench coat. Whoever was after her eventually catches up with them. She has information they want but dies while being questioned. They fake an accident by pushing Hammer's car off the road but he survives, waking up in the hospital two weeks later. As he investigates Christina's death he's told by the police to stay out of it but the hard-nosed PI proceeds anyways. Little did he know that Christina's secret would lead to death and destruction.