Mortal Engines is a steampunk science fiction film adaptation of the novel by Philip Reeve. Set in a post-apocalyptic world, the movie depicts large cities moving on giant wheels and preying on smaller towns in a system called Municipal Darwinism.
The story centers on Hester Shaw (Hera Hilmar), a young woman with a scar on her face who seeks revenge against Thaddeus Valentine (Hugo Weaving), a high-ranking official from the predatory city of London responsible for her mother's death. When her efforts fail, she meets Tom Natsworthy (Robert Sheehan), a young historian who is accidentally drawn into the conflict after learning a dangerous secret about Valentine's plans.
Hester and Tom then join a resistance group led by Anna Fang (Jihae), a rebel fighter who opposes the domination of predatory cities. They try to stop Valentine's evil plan to use an ancient weapon called Medusa to destroy the walls that protect the static cities in Asia.
The movie is filled with spectacular battles, unique steampunk technology, and an epic journey that reveals Hester's past and the secrets of a destroyed world. Ultimately, with courage and sacrifice, Hester and the rebels manage to thwart Valentine's plans, saving the world from further destruction.