Four years in the future, Peter runs through a bank of desolate warehouses to find a grimly determined Claire waiting for him with a gun. Peter wants to go back to the day it all started and fix everything, but Claire has another plan in mind. Claiming she always loved Peter, she pulls the trigger. Peter stops time, pulls the gun out of Claire's hand, and teleports to the present day.
Disguised in a hat and coat, Future Peter stalks into Nathan's press conference in Odessa, Texas, and shoots him twice, square in the chest. Present day Peter and Matt chase after the shooter. After ditching the gun in a supply closet, Future Peter teleports away, leaving Present Peter holding his hat and coat.
Devastated, Claire watches news of Nathan's shooting on TV. She wants to rush to Odessa to help, but Peter tells her to sit tight. Doctors kick Peter out of the operating room as they struggle unsuccessfully to bring Nathan back to life. When Peter is left alone to say goodbye, there's another shocker in store - Nathan sits up. He's alive!
The executive office of Yamagato Industries: now that Hiro has inherited of the company, he's bored and without a quest. He's just wondering when destiny will next knock on his door, when there's a knock at the door. The family lawyer hands Hiro a DVD with a message from Kaito. Hiro is to guard the contents of Kaito's safe, which he should never open, with his life. Like his father and grandfather before him, Hiro is to be the sentinel of a dangerous secret. The fate of the world depends upon it.
Claire packs a bag. Her breath is taken away when Sylar appears, claiming that she has what he wants. Claire makes a run for it, but Sylar prevents her from leaving the house, so she grabs a kitchen knife and locks herself in a closet.
Maya nearly clocks Mohinder with a cricket bat, mistaking him for Sylar. Now that Molly is safe, Maya hopes that Mohinder will finally "cure" her. Resigned to being unable to help, Mohinder starts packing for his return to India. Maya's eyes fill with blackness, and a light goes off in Mohinder's head. Maybe Maya's abilities don't originate in the blood as his father thought, but in the adrenal glands! Maya is relieved as Mohinder gets to work investigating his new theory.
Despite Ando's protests, Hiro opens the safe to find another DVD and a torn piece of paper, showing half of a chemical formula, which could destroy the world if it falls into the wrong hands. With a sudden gust of wind, the paper disappears, so Hiro stops time to investigate. Following a bizarre ribbon of plasma, Hiro comes face-to-face with a self-described Speedster, who chides him for not knowing the parameters of his abilities. She suggests that he ponder this when he gets back on his feet, punches him in the face, and disappears with the formula.
Matt finds Peter in the broom closet looking for the gun. Matt's already suspicious about Nathan's miraculous recovery, so Future Peter morphs to the surface to introduce himself, and explains that he had to stop Nathan from telling the world about them. Now that Matt knows, he needs to be somewhere else, so Peter makes him vanish. When Peter returns to Nathan's hospital room, Nathan has disappeared, too.
Outside the hospital, a reporter is taping a segment on Nathan's miraculous recovery, just as Nathan wanders behind him and into the chapel. Peter, holding a pistol, watches carefully in the wings, worried what his brother might reveal. Nathan explains to the congregation that he saw God, who has given him another chance to do His bidding. Announcing his noble goal to save the world by saving souls, Nathan falls to his knees and prays, the secrets of the Heroes still unrevealed. Peter pockets his gun and skulks off as the reporter gets it all on tape.
Mohinder shows Maya a syringe, which if his calculations are correct, should give instant powers to anyone. The serum will bond with an individual's blood chemistry, so abilities will manifest uniquely and in an infinite number of ways. He rushes off to the lab to run more tests, which indicate that he's finally hit the nail on the head. Exhilarated by his quantum leap, Mohinder contemplates using the syringe on himself, but Maya warns that it's evil, and begs him to destroy it.
Claire trembles in the closet as Sylar searches her house, promising that he doesn't want to fight; he merely wants what she has. Finding one of H.R.G.'s file boxes, Sylar pulls out a stack of Level 5 personnel files - a veritable shopping list of abilities he might want. Claire uses this distraction to attack, stabbing Sylar in the chest with the kitchen knife. He responds by pinning Claire to a wall and drawing a bloody line across her forehead.
Claire lies in shock as Sylar, having removed the top of her skull, probes her brain with his finger. When he finds what he came for, his stab wound heals. Sylar replaces the top of Claire's head, shocking her. Isn't he going to kill her? Sylar confesses that he couldn't kill Claire, even if he wanted to. She's different - special - and she can never die. And now, Sylar can't die either.
Suresh explains to Maya that he intends to isolate a serum that will give people abilities - and inject himself with it. Maya says it should be destroyed or it will fall into the wrong hands. Suresh says it's in the wrong hands now and that by experimenting on himself he'll be taking a quantum leap forward for science.
Peter takes Nathan back to his hospital bed, asking what happened to his plan to tell the world. Nathan professes that they might all be angels, but not if everyone knows about them. After Peter leaves, Linderman materializes, and Nathan recognizes him as his healer. Meanwhile, Governor Malden watches a TV news report of Nathan's miraculous recovery with Tracy, a dead ringer for Niki, who doesn't seem to recognize Nathan at all. Malden is delighted, convinced that they have found "their guy."
Finding himself in the middle of a desolate savannah, Matt stumbles across a rock painted with the image of the world splitting in two. Meanwhile, Ando wants Hiro to teleport to the past to consult Kaito about the missing formula. Hiro insists he will never visit the past again, preferring to see for himself how the world will be destroyed in the future. In the blink of an eye, Hiro finds himself in a war zone, where he and Ando battle for the formula. As the city crumbles, Ando kills Hiro, grabs the formula, and runs off.
The docks are dark and deserted. Mohinder stands at the water's edge, preparing to throw his syringe into the drink, but thinks the better of it and injects himself, immediately reeling to the ground. He regains consciousness in the midst of being mugged. Without thinking, Mohinder crushes the mugger's gun and tosses him 30 feet in the air. Amazed, Mohinder stares at his hands, contemplating his newfound abilities.
Angela leaves Nathan's bedside to confront Future Peter - what has he done with Peter, and why did he have to shoot his own brother? Future Peter insists that he had to try to stop Nathan, who set everything in motion. Since Angela can dream the future, she should know that the formula she and her friends tried to bury gets out and destroys everything. Now Nathan doesn't have to die.
Angela claims that it doesn't matter whether or not Nathan dies, because now Peter has screwed up everything. She no longer knows what the future holds. She orders Peter to go back to where he came from, but not before he tells her where Peter is. Future Peter tells Angela not to worry, Peter is someplace safe... Deep in Level 5, H.R.G stops tossing his ball, his ears perking to a screaming voice claiming to be Peter Petrelli.