Movie
Speed Demon
Narrative tropes
One Hero Changes Everything
highA demonically possessed trainload of passengers and a runaway locomotive constitute a crisis demanding collective response, yet Lu alone can act — Father Novak is incapacitated and every other passenger is possessed. The film's resolution hinges entirely on her individual faith and exorcism skill; without her the train crashes and everyone dies. Collective action is structurally absent.
About this trope: One exceptional individual matters more than institutions or collective action. Problems affecting millions are solved by a single remarkable person. Everyone else is passive.
Cultural messages
Be Yourself
mediumLu actively suppresses her religious calling — she took orders reluctantly, drinks heavily, and is in faith crisis. Her self-destructive arc signals the pain of denying her true nature. The climax (performing the first-ever nun exorcism) is a literal transformation scene in which she embraces the warrior-nun identity she had been repressing, and her authentic faith is the direct source of power that defeats Asmodeus.
About this message: A character hides or suppresses their true identity to conform, then finds strength and happiness by embracing who they really are. Authenticity is the real superpower.
Power Means Duty
mediumLu possesses an extraordinary and apparently unique ability — performing an exorcism as a nun. She spends most of the story resisting the responsibility her status and faith place on her (addiction, crisis of faith, reluctant ordination). The situation forces her to accept that her gift creates an obligation: she is the only one who can free the possessed and stop the train, and her identity arc resolves as 'warrior nun' defined by duty.
About this message: Those gifted with extraordinary abilities, wealth, or status have a moral obligation to use them for others — and the weight of that duty can be crushing. Privilege creates obligation.
Science vs. Faith
mediumThe central tension is Lu's crisis of faith versus the supernatural reality bearing down on her. Rational responses (the experienced priest is sidelined, no ordinary intervention can stop a demon-controlled locomotive) are useless; only a faith-based exorcism works. The climax demands a literal leap of faith from a self-described faithless nun, and the story validates that leap — spiritual action succeeds where nothing else could.
About this message: Characters face a choice between rational/scientific thinking and spiritual/intuitive belief. The story typically validates faith or emotion over cold logic — the scientist is wrong, the believer is vindicated.
Movies that share these tropes
Full plot (spoilers)
Sister Lu (Katie Cassidy) is a hard-drinking, self-destructive orphan who was raised by elderly priest Father Novak (William H. Macy) and reluctantly took holy orders. Struggling with addiction and a crisis of faith, she is far from a model nun. The two board a train traveling from Montreal to New York City. Early in the journey, a hapless male passenger unknowingly unleashes the demon Asmodeus by pricking his finger on a demonic statuette concealed inside a gift from his girlfriend. Blood contact with the statuette activates the entity, which begins possessing passengers one by one and seizes control of the locomotive, sending the train hurtling at lethal speed toward a dangerous bend in the track. With Father Novak incapacitated and the possessed passengers growing increasingly violent, Lu is the only one left to confront the demonic threat. Drawing on her lapsed but not entirely extinguished faith, she performs what the film presents as the first exorcism ever conducted by a nun, battling Asmodeus directly in an effort to free the possessed and stop the runaway train before it crashes. Her arc moves from reluctant, faithless ward of the Church to a 'warrior nun' who reconciles her inner demons with the literal one threatening everyone aboard.
Sources: IMDb (search/title page), Eye for Film review, Screen Anarchy preview, Bloody Disgusting trailer coverage, Wikipedia (article stub, no plot text)