The preview will be shown exclusively in theaters with "The Fantastic Four: First Steps." EW caught an early look with a group of reporters.

Box-office sensation "Avatar" is back with a third movie this December, teasing epic family drama and stunning new creatures in the first trailer.

Right from the outset, it's clear that "Fire and Ash" will be the most intense chapter in the "Avatar" saga yet. For the first time, we see hostility amongst the Na'vi clans, with Jake Sully (Sam Worthington) and the oceanic Metkayina clan drawn into a conflict with the Mangkwan clan, or Ash People, as they're also known.