Jumping forward several years from the events of Season 2, Season 3 takes place at the height of the War of the Elves and Sauron, as the Dark Lord seeks to craft the One Ring that will give him the edge he needs to win the war and conquer all Middle-earth at last.

In Season Two, Sauron has returned. Cast out by Galadriel, without army or ally, the rising Dark Lord must now rely on his own cunning to rebuild his strength and oversee the creation of the Rings of Power, which will allow him to bind all the peoples of Middle-earth to his sinister will. Building on Season One's epic scope and ambition, the new season plunges even its most beloved and vulnerable characters into a rising tide of darkness, challenging each to find their place in a world that is increasingly on the brink of calamity. Elves and dwarves, orcs and men, wizards and Harfoots... as friendships are strained and kingdoms begin to fracture, the forces of good will struggle ever more valiantly to hold on to what matters to them most of all... each other.

Set thousands of years before the novel in the Second Age of Middle-earth, the season depicts the emergence of the Dark Lord Sauron and the forging of the first Rings of Power.