When two dead bodies are found inside a wrecked car on the Golden Gate Bridge, Detective Lindsay Boxer doubts that it will be anything as simple as a traffic accident. The scene is more gruesome than anything she has seen before: it definitely wasn't the crash that killed these people. While Lindsay starts to piece this case together, she gets a call she wasn't expecting. Sightings of her ex-colleague-turned-ruthless-killer Mackie Morales have been reported. Wanted for three murders, Mackie has been in hiding since she escaped from custody. But now she's ready to return to San Francisco and pay a visit to some old friends.