Peter Jackson and Fran Walsh — the filmmaking pair behind the “Lord of the Rings” and “Hobbit” trilogies — return to the big screen with Universal and MRC’s “Mortal Engines,” based on the award-winning sci-fi book series by Philip Reeve.

The film will open on December 14, 2018, according to Universal. December 2018 is shaping up to be a competitive month, with what is suspected to be James Cameron’s “Avatar” sequel slated for release on December 21 by Fox. The first “Avatar” opened on the same week in December 2009.

Set in a dystopian future where Earth’s cities roam the globe on huge wheels, battling each other in a struggle for ever diminishing resources, “Mortal Engines” is the story of how two unlikely heroes come together and change the course of the future.

Jackson and Walsh co-wrote the screenplay with their “LOTR” and “Hobbit” collaborator, Philippa Boyens, who serves as co-producer. Zane Weiner, Amanda Walker and Deborah Forte also produce, while Ken Kamins executive produces. Universal will distribute the film worldwide.

That week of December has brought good fortune to Jackson: All six “Hobbit” and “Lord of the Rings” movies staked out the same pre-Christmas week date.