2. "What If... the Watcher Disappeared?" / "What If... What If?" (season 3, episodes 7 and 8)
As the seventh and eighth episodes of What If...? season 3 function as a two-parter, we're going to rank them together. It feels right, because they are two sides of the same story. They also don't function quite as well without each other.
"What If... the Watcher Disappeared?" catches us up with Captain Carter and Kahhori, who have joined forces with Byrdie The Duck, and Storm to form The Exiles. Upon saving Xandar, they discover that The Watcher has been removed from his post and is in danger. And with that, they attempt to save their friend. It's an interesting character moment for all of them, but it's Captain Peggy Carter who struggles the most, fearing losing another friend, and this produces some strong character work for a hero who is always so focused. It also forces her into action, as she asks an Infinity Ultron to help save The Watcher from The Eminence.
The battle begins in the finale and runs throughout the course of "What If... What If?" as The Watcher himself turns The Exiles into Watchers to help him defeat his former colleagues and mentors. In the end, it's Captain Carter who pulls it off, seemingly sacrificing herself in the process. And The Watcher, now using his real name of Uatu, continues to watch over the multiverse in his own way, giving things a little push or a helping hand if necessary.
These two episodes serve as an emotional and epic way to end the series. On their own, they aren't perfect, but together, they pull it off - sending What If...? out on a note that will have people talking about it for the longest time to come.