The episode opens with Mark, Eve, Oliver, and the other heroes going about their day, fighting supervillains and making the world a better place. However, the war from Season 3 has taken its toll on everyone.
At the Pentagon, Cecil sits in reflection, realizing that the world is beating them down at the worst possible moment. Mark, in particular, is on the verge of a breakdown, given how much he and the other heroes have suffered. The heroes' losses have made things more strained than ever for those left behind.
The relationship between Oliver and Mark is also strained, with Oliver lamenting how it always falls on them to save the world. Mark hasn't stopped fighting, and he's currently running himself ragged. Debbie encourages him to take the night off, but he's still wracked with guilt and feels like he needs to make amends.
Cecil believes that the only way to try and make things right is to re-form the Guardians. After what Cecil did with Mark last year, they're understandably guarded about this though. They do eventually agree, and while Brit will remain as team leader, the group vows to walk away at the first sign of Cecil's misdemeanors again.
But Mark isn't there, as he's called out to fight a new villain called Dinosaurus. The Dino taunts Mark, but things take a strange turn when the dinosaur changes into a scared guy. He claims the dinosaur just takes over and he can't control it, but Mark is loathe to let him go. That is, until the Guardians show up.
Mark leaves it to them and heads over to Eve's place for dinner. Unfortunately, things don't go much better. Eve's dad has lost his job after the war hit Chicago and he's not happy with Mark's part in all of this.
Mark accepts the berating in stride, dismissing the scathing jabs as he and Adam eventually venture outside for a chat. Puffing on a cigar, Adam brings up how tough Atom Eve is—but not quite tough enough. The sight of her in a broken, battered state at the end of season 3's finale has hit their family hard. The only two times Eve has nearly died have been at Mark's hands. "If you really care about her, maybe think of that," he says, his words cutting Mark deeply, especially after he nearly killed Dinosaurus earlier in the episode.
However, there are bigger problems to contend with here. It seems like Eve's powers aren't working quite as well as they should. Down in the sewers, a larger threat is growing in the form of Rus, who is being controlled by sequids who want to take over the entire city. To make matters worse, their reign of terror coincides with another Supe on the loose—Universa.
Universa attacks a power station upstate and starts channelling the power to maximum output. Unfortunately, this mass blackout begins spreading along the Eastern Seaboard. If the cooling system doesn't get power soon, they could be looking at a big meltdown. When Eve catches wind of what's happened, she alerts Invincible. Unfortunately, the sequids strike at the same time, causing quite the headache for Cecil and the others as they try to figure out which to hit first.
Unfortunately, Eve isn't much help as she realizes her powers aren't working properly. While Invincible and Eve fight Universa at the plant, the Guardians touch down in the city. They set up a perimeter, and Brit explains how they're going to take the goons out. They need to press a button and their neural disruptor will then shock all sequids within ten feet. Then they need to hit the people with a teleport dart to get them out of there.
Time is of the essence, and while Eve manages to smack Universa and knock her out, the plant workers show up and manage to get the power back up and running without catastrophe. While Eve hangs back, Mark is called out by Cecil to try and help stop the sequids.
Out in the streets, Rex defies Brit's orders and heads down into the sewers, believing that there may be more sequids down there. Rex certainly does find more of the sequids down there taking human hosts. After a bit of a close call, he manages to come out in one piece.
While Eve heads home, Mark takes out Rus and saves the day from the sequids before the dome's integrity collapses completely. However, instead of waiting for the disruptor to be rushed over to him, Mark makes the shocking choice to kill Rus outright. Is Invincible turning to the dark side?
