During an arrest on a train, the leader must lead his team through the full speed train filled with flesh eating demons to the engine car, where they must find a way to get off the train before it crashes.
The whole point of getting to the engine car was to stop the train.
“When the train’s passengers turn into flesh-eating demons, an FBI agent must lead a rag-tag group of survivors to the engine room to stop the out of control locomotive and escape.”
A quick attempt to smooth and clarify it:
After a portal to hell opens on a commuter train (or whatever explains the demons), a junior FBI agent, his team, and a captured criminal battle for their lives against flesh-eating demons.
Junior is an example of irony or extra conflict from the protag. He cannot just be “a leader.”
The crashing part sounds better as an escalation for the second half of the script and wouldn’t need to be in the logline. There’s more than enough conflict in the first half to battle the demons and try to save lives and try to escape in general. Another way to look at it is that the logline should have one objective. Defeating the demons and getting to the engine car are two.
If the story really goes for max conflict early on, consider:
After a portal to hell transports flesh-eating demons onto their train and sends it out of control, a junior FBI agent must lead his team and a captured criminal to the engine room to stop it before it crashes.
That technically works, but it’s a lot and it highlights the other concern that the demons become secondary.
Is there a good reason why the FBI takes a criminal on a train? They say a story should have just one hook or what-if? or coincidence and here it’s ‘demons on a train.’ The FBI part sounds like a second instance and disconnects me from the idea.
How many are on the team? How many are needed for one criminal? Is there something important about the criminal that needs to be said?
The other thing about the FBI agent is that he doesn’t represent the typical reader who would imagine him or herself in this novel scenario. If the story were truly about an FBI matter that escalates, then of course he’s fine. But when the hook is ‘demons on a train,’ is an FBI agent a dramatic or fun choice for protag?
Wait, first you replied that it’s not the FBI and then wrote FBI team. So which is it? If it’s not the FBI, the logline has to say what kind of team it is. Otherwise, it’s vague and confusing.
The criminal part might even be a third objective. Is it of major importance that he survive? (That’s movie morality, not my own!)