Afraid of losing the love he thinks he's found, Peter denies his past and doesn't look in the box while an unknown woman tries to track him down. Parkman and Nathan are led to Philadelphia to track down Matt's father, unknowingly being led into a trap where Nathan stumbles into the city that blew up after all. Mohindar takes Molly to the Company in search of help for her, just as Nikki shows up, while another hero begins to discover her powers in Texas.

Peter Petrelli finds himself in a future New York City where a virus has devastated the world's population. As he gradually regains him memory, he recognizes his mother who urges him to use his Hiro-like powers to go back in time and stop the virus before it begins. Claire and West's relationship reaches a crisis point when West realizes that her father is the same man who once kidnapped him. Suresh's loyalty to HRG man is starting to wear thin and he finally admits what he has been up to. Nathan learns that brother Peter is alive. Matt Parkman finally confronts his father in an attempt to release Molly from her coma-like state. Having fallen out completely with Takezo Kensei, Hiro attacks White Beard's camp. A new character with a familiar face, Adam Monroe, is revealed as one of the founders of the company.

Hiro learns of his father's death and travels back in time to save him only to realize that he must let events unfold as fate intended. He does however recognize his father's killer. Matt Parkman realizes that he has the ability to implant thoughts in other people's minds. He wants to know the identity of the woman in the photo with his father. When Bob and Suresh kidnap Claire Bennet, HRG and West set out to rescue her but get their own bargaining chip beforehand.

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.

Tracy and Nathan try to save themselves from a dangerous Mohinder who wants to use their synthetic power laced DNA to find a way to remove Mayas/his own powers. Mohinder turns to the dangerous, power-stealing Arthur Petrelli to help Maya, and in return, Mr. Petrelli asks for Mohinder's help in developing the secret formula to give people powers. Meanwhile, Sylar is given the task by the comatose Angela to save Peter from Arthur at Pinehearst, where he was captured and rendered powerless by his him. Also, Daphne is ordered by Mr. Petrelli to kill Matt, but finds the task difficult as she begins falling in love with him as he predicted. In Africa, Hiro is still searching for answers from the spiritual painter about who is behind Pinehearst and what their nefarious plans are for the world. In California, Elle approaches Claire and asks for her help to control her powers which leads to both of them forming an uneven alliance to venture to Pinehearst in New Jersey to find answers. Also, H.R.G. recruits Meredith as his new sidekick to track down more Level 5 escapees.