A egotistical and super-charged Sylar goes to the Company to kill all the leaders, and inadvertently releases 12 super-powered criminals from the place's notorious Level 5 prison block during a fight with Elle. Peter, trapped in the body of one of the criminals, is set free as well and is forced to team up with a group for a crime spree. Meanwhile, Future Peter tries to fix his mistake with Nathan, as Angela takes over the company in the wake of Bob Bishop's murder and frees Noah Bennett to help the Company track down the 12 escapees and bring them back or eliminate them. In California, Claire learns more about her powers as she recovers from Sylar's attack. Hiro and Ando travel to Paris to track down speedster Daphne Milbrook who robbed them and learn that she is working for a darker power. In New York, Maya discovers that Mohinder's injection has changed him by making him super-strong, but also altered his personality. In Africa, Matt meats Usutu, an African shaman with a familiar power of painting the future. Elsewhere, Tracy learns that she has the power to super-freeze anyone and anything while dealing with a hounded tabloid reporter seeking any dirt on her and the shady Governor Maldon who are continuing to groom Peter for a position in the U.S. Congress.

Claire attempts to destroy her first target, Stephen Canfield. Hiro attempts to become friends with Daphne.

Fellow villains Knox and Daphne are sent by their emissary, Maury Parkman, on a quest to recruit Hiro and others to the Pinehearst fold. Adam Monroe is brought before the ringleader, who turns out to be the most powerful villain, who uses his power to heal. Matt Parkman arrives back in New York from his African adventure, and is confronted by Daphne with an offer to join their organization, but he instead wants a commitment from her. Hiro and Ando teleport to Africa to try to make contact with Usutu, the vision painter, for information on the persons behind all the recent events. Angela and the Company are paralyzed from recent events, and Noah Bennett is forced to team up with Sylar again to hunt down more escapees from Level 5. Peter goes to Pinehearst searching for answers, but is stunned to learn that his father, Arthur Petrelli, thought to be long dead, is the ringleader of the whole events, and who as the ability to physically absorb others powers by mere touch. Meanwhile, Claire and Sandra go on a mission to save Meredith from the clutches of Eric Doyle, a villain with abilities to control people mentally and physically. In New York, Nathan and Tracy try to trace their origins with Mohinder's help, but who has other plans for them.

Having reestablished control over the Company, Angela sends Nathan and Peter to Haiti to find the power-suppressing Haitian to bring him back to the USA to help in their fight against Arthur Petrelli and the evil Pinehurst. Hiro and Ando travel to New York to come back into the fold and ask for Parkman's help. Hiro, having lost part of his mind, but not his powers, teleports himself, Ando and Parkman to Kansas to Daphne's home to find out what Mr. Petrelli has on her. Also, Sylar teams up with Elle to try to capture Claire to bring her to Pinehurst to give her to Suresh to experiment on as the missing catalyst to the formula. But everything changes when a prolonged solar eclipse happens, which renders the heroes and villains powerless, stranding Peter and Nathan in Haiti with the Haitian who is trying to capture the powerful Voodoo witch-doctor Baron Samedi. In Kansas, Parkman must find a way into the Millbrook house without his mind-reading powers, and learns what Daphne is without her super-speed powers. In California, the powerless Elle and Sylar try to capture Claire, who accidentally gets shot, and Nathan seeks revenge.

Noah, Claire, Angela, and Meredith find themselves trapped at the Primatech by Sylar who locks them in the building and subjects them all to various mind games. Meanwhile, Matt, Daphne, and Ando seek refuge at the Mendez loft where Daphne plans to steal a sample of the power-giving formula to give to Ando who wants to rescue the powerless Hiro still trapped 16 years in the past, who continues to struggle to find his true origins with his younger self. Back in the present, Peter faces off against Nathan, Tracy and the security detail at Pinehurst to stop Mohinder from reproducing the formula, and finds allies in the form of Knox as well as Flint who also want to stop the production of the formula, leading to a fiery showdown for all.

Following a tip from their anonymous source "Rebel", Matt and Peter hurry to rescue Daphne from the holding facilities in 'Building 26' in Washington, and to find evidence that may expose the government's plans to capture those with powers. Meanwhile, Sylar uncovers the truth about his mother after he experiences past memories of his father at a disused diner located deep in the New Mexico desert which makes him dump Luke and head off to look for his biological father. In California, Claire must find a way to sneak Alex out of her house which is under observation by FBI Agents, and Mrs. Bennet reluctantly agrees to help. Elsewhere, Danko hatches another nefarious and explosive plan of his own to trap and kill Matt. Also, Claire has a run-in with an old villain, Eric Doyle, whom she captured a while back who asks for her help to hide from government assassins after him too.

Now on his own, Sylar finally finds his biological father, Samson Gray, a reclusive, lung-cancer ridden taxidermist, to confront him with questions about his past, but soon learns that Samson is not who he appears to be. Meanwhile, Nathan continues to lock horns with Danko over the hunter's tactics to eliminate people with abilities, after he tries to frame Parkman for an attempted suicide bombing. This leads to both Nathan and Danko going behind each others back to unseat the other. Nathan becomes wary about Danko going rogue and the hunter interrogating Tracy, as well as Nathan's mother, Angela, about Nathan's own ability. In California, Claire takes Alex's old job at the comic book store where she is given a message by 'Rebel' to help out her former nemesis, the puppet master Eric Doyle, when he too is targeted by rogue agents. Also, Hiro and Ando return to California where they are led by clue from Rebel... to an infant Matt Parkman.

The identity of "Rebel" is revealed with chilling consequences - Emmy Award-Winner Zeljko Ivanek, Brea Grant and Swoosie Kurtz Guest Star.

H.R.G. is greeted by some unexpected visitors and Samuel's grand plan begins to come to fruition. Meanwhile, Peter struggles to accept the truth and takes extreme measures to get what he wants. Elsewhere, Claire's journey leads her to an unexpected destination.

Samuel goes off and tries to bring Emma into the fold by manipulating her about how special her sight-of-sound powers are, while back at the Sullivan Brothers Carnival, Claire becomes more suspicious about Samuel's intentions and deals with not only Samuel's right hand, Replicating Man, Eli, but also the Puppet Master Eric Doyle. A delirium-stricken Hiro returns to Japan and tries to convince Ando in code-talk to help rescue Mohinder from a lunatic asylum in Florida where Hiro forcibly placed him for protection from Samuel.

Claire attends Nathan's funeral while Peter struggles with his grief in his own way by wanting to seek revenge. Meanwhile, Noah and Lauren interrogate a captured Edgar for information to where to find Samuel's carnival. Elsewhere, Sylar returns to Samuel's carnival where he and Lydia try to find a way to emotionally get inside the killer's head to make him see what is troubling him.

H.R.G. enacts his plan to take down the Carnival with the help of Lauren and Suresh. Sylar visits Matt looking to understand his desire to make a human connection, but Matt has a plan of his own. Meanwhile, Peter warns Emma of Samuel's intentions after his grim vision of the future.

Samuel's ultimate plan spells disaster for thousands.