WARNING: The following contains spoilers for What If...? Season 1, Episode 5, "What If… Zombies?!" streaming now on Disney+.
In the Marvel Cinematic Universe, one of the major points of interest was what would happen to Captain America's shield once Steve Rogers decided to pass it down. It was a hot topic in the comics that saw Bucky Barnes wield it after his death, with Sam Wilson taking up the mantle later on. Now, while the MCU has changed this up drastically, with Sam diplomatically getting the shield and Bucky having no interest, What If...?'s latest episode, "What If… Zombies?!" puts its own spin on things, indeed crowning a new Cap, but in the goriest manner possible.
With this alternate reality steeped in a zombie apocalypse, Steve Rogers is seen pretty early on being infected by a zombified Hank Pym. This undead Cap represented the beginning of the end for the Avengers, culminating in Sam also getting infected.
Later in the What If...? episode, Zombie Falcon attacks Bucky and the remaining heroes at Grand Central Station as they try to board a train to New Jersey. The ex-Winter Soldier watches Okoye eventually cut Falcon in half, but things get dire as they embark on their journey.
Zombie Cap sneaks onboard their train, mauling and infecting Sharon Carter. Bucky hears her screams and runs in, only to meet a snarling, bloodthirsty Cap. "I think you've had enough, Cap," he remarks before meeting a charging Steve head-on. As Steve blocks all of Bucky's bullets with his shield, it comes down to a slugfest, with Bucky punching Cap away to the end of the train and taking Zombie Sharon down temporarily.
This results in Steve flinging the shield at his buddy, only for Bucky to catch it and throw it back in one motion, akin to his high-velocity throw when he fought Steve in The Winter Soldier outside his apartment on the rooftops. Only this time, Zombie Cap doesn't catch the shield -- it slices him in half as it gets stuck in the exit door.
It's a tragic scene, as both halves of Steve's body then fall slowly onto the tracks, leaving Bucky to grab the shield as he remarks, "Sorry pal, guess this is the end of the line." It nods to their iconic MCU exchange and overall dynamic, where they've sworn to stand with each other until the mission's done. In What If...?'s case, it's a gutsy and bloody passing of the mantle, as there's no one else to take up the position.
While Bucky doesn't don the red, white and blue in What If...?, as he takes the shield up, he begins his stint as the new Sentinel of Liberty to honor his fallen comrades. With his Infinity War suit, Bucky leads them into battle later on against Vision, but sadly, a zombified Wanda takes him out too, reminding viewers that not even a super-soldier like Cap can withstand the rampage of the undead.
To see Bucky finally wield the shield, What If...? releases new episodes every Wednesday on Disney+.