Val is under federal investigation for illegal supersoldier experiments, so she sends Yelena, Walker, Ghost and Taskmaster to take out her secret research labs all over the world.
In-between missions, Yelena visits Red Guardian and talks about the growing “void” inside of her. He runs a limo rental service now.
Val sends the four to a desert base so they will also kill each other and tie up all her loose ends. Red Guardian finds out while chauffeuring for Val, while her assistant Mel tips off Congressman Bucky.
At the base, Ghost immediately headshots Taskmaster and loots her gear. The surviving three run into Bob, one of Val’s failed test subjects, and they all team up to survive when they realize Val wants them all dead. Yelena bonds with Bob.
Val sends soldiers to the base, so Bob sacrifices himself to distract them while Red Guardian rescues the others. Turns out Bob actually has superpowers and survives, so Val orders him captured and delivered to the Avengers Tower, which she bought and rebranded “the Watchtower”.
Bucky rescues the group from pursuing soldiers and recruits them to take out Val and rescue Bob. Red Guardian names them “the Thunderbolts”. Meanwhile, Val convinces Bob to become the Sentry by acting motherly and claiming she can make him the world’s most beloved superhero.
The Thunderbolts attack the Watchtower, fight soldiers and confront Val, who sends the Sentry after them. He easily defeats the team, but refuses to kill them. When Val presses for him to do it and begins insulting him, the Sentry turns on her, so she triggers a kill switch she built into his suit.
The Sentry survives, snaps and turns into his evil the Void, then creates a literal void over the Watchtower and begins pulling people in it, trapping them in suspended animation eternally reliving their worst memories to feed off their suffering.