After the battle between Pinehearst and Primatech, Pete, Claire, Matt, and Daphne try to live normal lives, while a powerless Hiro tries to teach Ando how to use his new special ability and become a superhero. However, Claire discovers Nathan's plan to track down those with abilities.
Peter and Nathan face off after the battle with their father; Sylar detains Claire, Noah, Meredith and Angela at Primatech, and Mohinder may hold the key to rescuing Hiro.
Hiro and Claire go back in time to the moment Noah took Claire from Kaito Nakamura; Sylar interferes with Peter and the Haitian's attempt to defeat Arthur; and Suresh makes major progress with the formula.
Conclusion. Elle and Sylar face Noah, who's out for revenge; Peter and Nathan help the Haitian with his brother (Demetrius Grosse); and Ando, Sam and Frack try to restore Hiro's memory using a comic book.
Part 1 of 2. Arthur sends Sylar and Elle after Claire; Matt, Hiro and Ando follow Daphne to uncover her secret; Nathan and Peter search for the Haitian in hopes that he can stop their father. Seth Green and Breckin Meyer guest star.
Nathan learns of his father's plans, while Flint and Knox launch attacks on Hiro, Ando, Peter, and Claire. Meanwhile, Matt tries to revive Angela, Sylar meets with Elle, and Mohinder begins testing of his newest superpower formula.
Hiro attempts to delve into Arthur Petrelli's past to uncover the mystery behind him creating a rival company Pinehearst and his hatred towards Angela. Sylar stricken by guilt tries to stop his murderous ways with HRG and Elle vying for his blood. Meredith's training goes up in smoke with the arrival of her brother.
Tracy and Nathan try to save themselves from a dangerous Mohinder who is no longer in control of himself. Sylar is given the task to save Peter from a rival company. Daphne is ordered to kill or be killed. Hiro is still searching for answers.
Villains Knox and Daphne are on a quest to recruit Hiro and others to the Pinehearst fold. Angela and the Company are paralyzed from recent events. Peter goes to Pinehearst searching for answers but is stunned to learn who the founder is. Claire and Sandra go on a mission to save Meredith from the clutches of Doyle, a villain with abilities to control people mentally and physically. Nathan and Tracy try to trace their origins with Mohinder\'s help.
Matt catches a glimpse of the future, Claire closes down on her first villain, but so are others, Peter finds that his visit to the future has changed him, and Hiro and Ando try to bond with Daphne.