What are the recognizable tropes to a "train heist", or more broadly the action sequences where a protagonist boards a moving train in order to stop it?
My protagonist is the unreliable guile heroine who has been playing at hero the entire book. She typically over-inflates intrigue, misreads clues, and bumbles her way through moral conundrums. She alternates between 4D chess and being able to manipulate people by reading their reactions – meaning she has been making it up as she goes. At this point she's no longer sure if she's running a long con or actually becoming a hero, but she knows she's not going to be left out.
Unfortunately I have plotted a very trope-y action climax, but now that I write it, I realize the standard action-hero tone feels wrong so I need to identify the main tropes in order to subvert them. To be clear the protagonists do board the train and it does stop – that still has to happen so it's not a failed trope.
How do I subvert the tropes of a train heist?
The responses are becoming random so I've picked the top answer which addresses the question about train heist tropes.
The question is about identifying established tropes in order to invoke and subvert them, not asking to suggest random surprise endings that avoid these story elements altogether – which would be too broad for this site anyway.