Season 2 of Amazon’s Lord of the Rings prequel is going to building up to a major moment in Middle-earth history.

Screenshot: Amazon

When The Rings of Power returns this August, it’ll bring to life a climactic conflict that has long been a turning point in J.R.R. Tolkien’s Lord of the Rings chronology—not the battles of the final alliance to lay Sauron low, but the climactic war that set the stage for the rest of the Second Age.

The War of the Elves and Sauron, as it is plainly put in the various appendices and apocrypha of Tolkien’s Middle-earth works, marks a significant turning point in Sauron’s renewed plans for Arda. Having successfully wormed his way into Eregion, the heart of Elf-kind’s kingdoms in Middle-earth, Sauron—in the guise of Annatar, the Lord of Gifts—successfully convinced Eregion’s lord, the master forger Celebrimbor, to take part in his plans to forge almighty rings of magical power.

But Celebrimbor made a choice that would save Middle-earth from complete destruction and dominance under the Lord of Mordor: while Annatar instructed and guided him in the making of 16 rings (nine to be given to the realms of men, and seven to the Dwarf-Lords) Celebrimbor used the techniques he’d learned from Annatar to forge three more rings for the Elves—Narya, Vilya, and Nenya—completely away from Annatar’s knowledge or the malignant magics that would allow him to control them through the One Ring he had forged himself in Mordor. With the Elves discovering Annatar’s true identity the moment he attempted to use the One Ring, over a hundred of years of planning and influence fell apart… and the now-revealed Sauron decided to take what he wanted from the Elves by force instead.

This conflict will form a major element of The Rings of Power’s second season, condensing the show’s time frame of the thousands of years in the Second Age to move on from the initial forging of the rings, glimpsed at the climax of season one, into the story of how they nearly laid all of Middle-earth low for the first time. We’ve seen glimpses of key moments in this conflict already recreated in our first proper look at Rings of Power season two—and while we don’t know all that much about the nearly decade-long war from Tolkien’s material, we know enough to put a lot of it together with what we might see on screen already, when The Rings of Power returns to Amazon August 29.