MULTIVERSE

Why it matters: Xavier, Magneto, Cyclops and Mystique. Stewart, McKellen, Marsden and Romijn all return in Doomsday. On Disney+’s official “before Doomsday” list.

Why it matters: Alan Cumming’s Nightcrawler, confirmed for Doomsday. On Disney+’s official “before Doomsday” list.

Why it matters: Kelsey Grammer’s Beast, who is back for Doomsday.

Why it matters: Young Charles Xavier and Erik Lehnsherr in 1962. How the friendship and the war between them began. Recommended by marvelwatchlist.

Why it matters: Time travel and both X-Men casts. The closest thing to a multiverse primer.

Why it matters: Wolverine’s farewell. Deadpool & Wolverine opens by digging up this Logan’s grave.

Why it matters: The Russos’ first Avengers epic. Doomsday is built the same way.

Why it matters: Tony’s sacrifice and Steve’s ending. The emotional set-up for everything since.

Why it matters: The multiverse cracks open with villains and Spider-Men from other universes.

Why it matters: The TVA, variants, and how the multiverse broke open.

Why it matters: A primer on alternate universes, narrated by the Watcher.

Why it matters: Names the Incursion, the event Doomsday is about, and cameos Patrick Stewart’s Professor X.

Why it matters: Its mid-credits scene opens a door to the X-Men universe.

Why it matters: Loki’s fate at the heart of the multiverse.

Why it matters: The TVA, the Void and Gambit (Channing Tatum, confirmed for Doomsday).

Why it matters: Marvel’s First Family, from another universe and headed for Doomsday.