The full story
Nine standalone episodes, narrated throughout by the Watcher, each asking one question about a single MCU turning point and following it to its own ending. They read as unconnected — until the finale reveals they've been building toward one story anyway.
1. Captain Carter Were the First Avenger? — Peggy Carter takes the super-soldier serum instead of Steve Rogers, becomes Captain Carter, and is thrown nearly seventy years into the future mid-battle, waking up to Nick Fury and a very different world.
2. T'Challa Became a Star-Lord? — Ravagers grab T'Challa instead of Peter Quill in 1988. Grown into a heroic Star-Lord, he pulls off a heist against the Collector for the Embers of Genesis and reunites with his Wakandan family.
3. ...the World Lost Its Mightiest Heroes? — Someone is killing the Avengers Initiative's recruits one by one. Nick Fury traces it to Hank Pym, avenging his daughter's death — and Loki, arriving to avenge Thor, allies with Fury and chooses to rule what's left of Earth instead.
4. Doctor Strange Lost His Heart Instead of His Hands? — Christine Palmer dies in a car accident Strange can't prevent. Mastering time manipulation trying to save her anyway splits him into two selves — one accepts her death, and the one who won't becomes Strange Supreme, powerful enough, and broken enough, to unmake reality trying to fix it.
5. Zombies?! — A quantum virus turns Hank Pym and Janet van Dyne into the outbreak's first victims. Survivors led by Bruce Banner and Hope van Dyne fight their way to Camp Lehigh for a cure built from Vision's Mind Stone, through a zombified Wanda Maximoff and a zombie Thanos waiting in Wakanda.
6. Killmonger Rescued Tony Stark? — Killmonger saves Stark from the Ten Rings instead of Iron Man doing it alone, then spends years turning that favor into T'Challa's death, Rhodey's death, and eventually Stark's — taking the Black Panther mantle for himself before Shuri and Pepper Potts catch on.
7. Thor Were an Only Child? — Odin never adopts Loki, and an only-child Thor grows into a party god throwing a rager on Earth big enough to draw Jane Foster and Carol Danvers — and, in the mid-credits, an Ultron who already holds every Infinity Stone.
8. Ultron Won? — That Ultron wins outright: the Avengers fall, the Stones are his, and nuclear war follows. Hearing the Watcher's own narration is what tips him off that a multiverse exists to conquer next — Hawkeye and Black Widow's last move is waking Arnim Zola's consciousness to slow him down, and it's only enough to slow him.
9. The Watcher Broke His Oath? (finale) — The Watcher breaks his rule of pure observation, pulling Captain Carter, Star-Lord T'Challa, Strange Supreme, Party Thor, Killmonger, and a Gamora who killed her own Thanos into the Guardians of the Multiverse to stop Ultron before he reaches everyone else's universe. Zola brings Ultron down from inside; Killmonger turns on the team anyway. Strange Supreme and the Watcher seal the Infinity Stones away — and a mid-credits scene puts someone new inside the Hydra Stomper armor.