Complex sentence: The corrupt cop appears to be a rapist who sexually assaulted the mysterious girl (Isobel) in the subway station; immediately after the sexual assault she stabs him and the cop falls to his death on the subway tracks.
Split into simpler sentences: The corrupt cop appears to be a rapist who sexually assaulted the mysterious girl (Isabel) in the subway station. Immediately after the sexual assault, she stabs him and the cop falls to his death on the subway tracks.