What does the end of commuter rescue mean? What is the main story of this film?

The film is set on a commuter train, with businessman Macaulay (liam neeson).

I met the "mystery passenger" Joanna (vera farmiga

Decoration). Joanna offered Macaulay an attractive task-finding a passenger in the car and getting a lot of cash in return. But in the process of searching, Macaulay gradually found himself involved in a fatal and dangerous situation. Whether he can successfully escape from this "terrorist train" and what shocking conspiracy is hidden behind it. As the train continued to accelerate, the truth was revealed one by one. ......