The Lord of the Rings: The Rings of Power's showed how the peaceful, sleepy region of Middle-earth known as the Southlands became Mordor, the seat of power for the Great Evil that defined the Third Age. J.R.R. Tolkien never offered much insight into Mordor before Sauron turned the region into a smoking hub of villainy, and while The Rings of Power tried valiantly to hide its big twist, plenty of viewers quickly deduced the Southlands was actually Second Age Mordor. After several episodes of narrative foreshadowing and subterranean construction, that transformation finally begins in The Rings of Power season 1, episode 6 ("Udn") after Adar outsmarts Galadriel and Halbrand.

Essentially, an ancient key switches on a dormant Southlands volcano. The resulting cataclysm brings forth ash, steam, fire, rock, water and, most of all, misery, and by The Rings of Power season 2, the transformation of the Southlands is well underway. However, even...