In the movie, Ran starts to have nightmares about her mother's death. Her father, Kogoro Mouri, receives a threatening letter that warns him of 12 "targets." Each target has a number in their name that corresponds to a playing card, and the targets are being eliminated one by one.
Conan soon realizes that all of the targets have some kind of connection to Mouri, whether it be through work or personal relationships. Meanwhile, Ran starts to remember a traumatic event that occurred 10 years ago involving her parents and herself. She begins to piece together the truth about her mother's death and the motive behind the attacks on her father's associates.
As the body count rises and the targets become more personal, Conan and the police race against time to uncover the identity of the culprit and stop them before all 12 targets are eliminated. The mystery twists and turns, leading to a shocking reveal of the killer's identity and their sinister motive.