Xjyuk

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?

I think the tropes are galloping horse, convenient boarding point, leaping from horse to train (and horse then veering off), a harrowing dangerous trip across the top of the train to get to the engine (perhaps almost falling off, perhaps with a gunfight or fistfight), holding the conductor at gunpoint to stop the train, or while the MC stops it himself. In the city or with a modern train, throw in a tunnel so the MC has to duck or lose his head. Also a convenient way to dispatch an opponent with his back to the tunnel.

The second part of the trope is the heist works; I've seen that subverted at least once (the train was decoy, the actual treasure went by another route).

Subvert the trope by making something the opposite of the trope.

No galloping horse: I've seen helicoptering onto a train. You could use something besides a horse (or the modern equivalent, a motorcycle or car).

No convenient boarding point: The hero can't figure out how to get ON the damn train. This might lead to a comic series of figuring that out (fail fail succeed), but probably doesn't fit your plot of boarding a specific train.

I've seen the harrowing trip to the engine subverted: MC boards on the caboose in disguise as a train employee, then just walks through cars to the front.

I've seen stopping the train subverted: MC pulls a pin to disconnect all the cars from the train, they coast to a stop while the engine races ahead. (I wonder if this is physically possible on a moving train, but ... liberties of fiction.)

You could subvert the trope with a plot twist: The train is an hour late, the conductor tells the hero he got stopped and robbed four hours out of the station. The gentleman that took it said if a woman tries to rob me, he will see her in San Francisco.

You could subvert the trope by blocking the track with something highly visible, so the conductor stops the train voluntarily out of caution. Maybe she tricks the conductor into stopping the train.

She could actually derail the train (dynamite the track).