WARNING: The following contains spoilers for What If...? Season 1, Episode 5, "What If… Zombies?!" streaming now on Disney+.
During WandaVision it was truly heartbreaking to see Scarlet Witch keeping Vision in Westview, her fake reality sitcom world. While he was sentient, he was for all intents and purposes mindless, with Wanda inputting memories into him, controlling him as if he were a jolly zombie. Well, come "What If... Zombies?!" the script is totally flipped in term of captor and captive, and by the time we see their final fates, it's even more heart-wrenching.
Now, WandaVision definitely crushed hearts as it played on House of M, with Wanda eventually having to accept the villain she'd become, leading to her disintegrating her family to go back to the real world. She knew the façade that she made to cover up her grief after the bot died in Infinity War needed to end, and ironically, Vision undergoes a similar journey of loss and mental anguish in this alternate reality.
When the remnants of the Avengers arrive at a S.H.I.E.L.D. military base in New Jersey, they find Vision is actually the one running it. However, while it seems like the bot's using the Mind Stone to try to cure humans infected with the zombie virus by manipulating their brain waves to fix their bodies, Bucky stumbles across his more sinister plan. He finds T'Challa, who's missing a leg, and Black Panther shockingly admits he was kept alive by the android, only to be fed to Wanda.
The notion riffs off of Marvel Zombies, where an undead Wanda, working for Kingpin, kept guard as the remains of Vision's body were used to jam radio signals in that apocalyptic universe. Vision was so out of it that he kept begging her for a kiss, not realizing the monster she'd become, which is a callback to the undead Wanda he's harboring here.
Sadly, when Bucky and Black Panther get out and reveal the truth to everyone, Vision has no defense. He admits he's been luring the living here with a signal and while he's worked to cure Scott Lang, he can't -- or won't -- cure everyone else, as he needs meals for a Scarlet Witch he can't return to human form.
Bruce Banner is appalled, chiding him for how many innocents he's sacrificing in this sadistic scheme in the name of love. It gets even deadlier when Wanda escapes her holding cell and starts attacking the heroes, including Vision, because she's not hungry for love -- she just wants to feast on flesh. This is a wake-up call, as Vision realizes the error of his ways, trying to redeem himself by bringing the base down on her.
It's his Westview that's now crumbling down, but it gets darker as he pulls the Mind Stone out so Bruce can use it to possibly find a cure. Unfortunately, while Vision dies giving the heroes and humanity a fighting chance, Wanda rises back up, ready to maul the remainder of mankind, all because Vision clung to the notion they could still have a perfect life together.
What If...? releases new episodes every Wednesday on Disney+.