What is the main drama of the movie "Midnight Meat Train"?

This film is the first bloody work of Godzilla director Ryuhei Kitamura in Hollywood, which is based on clive barker 1984 thriller short story of the same name. It tells the story of a photographer played by Bradley Cooper looking for a murderer on the subway. Midnight city, dark subway, terrible killer doing his routine work every night ... why did he kill people cruelly? What about the bodies of the victims? Next stop, death.

Midnight Meat Train Stills (13) For a photographer, the camera is his eyes, and it can always capture some shocking life fragments that are neglected by people ... As far as Leon Kaufman is concerned, the little-known but ambitious and ideal photographer's favorite thing is to shuttle through the streets of new york, especially at night, and freeze the life of the residents in this city on photographic paper. Leon's efforts caught the attention of Susan, the owner of a famous art gallery. She especially likes the excitement and incitement in his latest works, encourages Lyon to record the tougher and darker side of human nature, and promises to hold a unique solo exhibition for him in the city gallery if he meets his requirements. Lyon, who has doubled his confidence, firmly believes that he has entered the track of success and will eventually reach his long-awaited destination ... He began to wander around the city harder and never dared to leave the camera for a moment, fearing that he would miss something and regret it for life. Late one night, Leon dragged himself into a subway station. As he walked, he accidentally caught a mysterious man with a handbag and a cold face. What he can't imagine is that this photo finally leads him to the hunting circle of a serial murderer mahogany, who is looking for passengers who take the subway late at night. Because of the cruelty of the means used by the murderer, it brought an uneasy sense of death to the whole city. After determining the specific identity of the murderer, Lyon got deeper and deeper in the criss-crossing subway line like a demon, completely ignoring the worries of his anxious girlfriend Maya ... Lyon finally stepped into the abyss of pure evil, and Maya was also unnecessarily implicated.