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.

In flashbacks, we learn what happened to the heroes in the four months after the events at Kirby Plaza. Maja learns of her deadly powers at her brother Alejandro's wedding. Niki starts a Company-sponsored drug program but stops taking the medication only to realize that another hidden personality has emerged. Imprisoned by the Company, Peter Petrelli meets the now familiar Adam Monroe and we learn how he ended up in the shipping container destined for Ireland.

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.

Peter Petrelli and Adam Monroe track down another founding member of the Company and learn the location of virus 183. Maya learns how to control her powers but Alejandro' distrust of Sylar leads to a deadly confrontation. Niki returns to New Orleans and tells Micah about her medical condition. When his backpack is stolen, Micah and Monica set off to retrieve it, but things don't work out as planned. Hiro decides to avenge his father's death and goes after Adam. Claire, grieving over her father's death, decides to go public with her powers in a bid to stop the Company.

Nathan, Matt, and Hiro confront Peter and Adam at the Company's facility in Odessa, TX where Adam's intentions become apparent. Micah confides in his mother and working together; he and Niki set off to rescue Monica but with deadly results. Maya and Sylar visit Dr. Suresh and she finally realizes what Sylar is really up to. Noah Bennet visits his family and begs Claire not to publicly reveal her secret.

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.

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.

Under the guidance of Usutu, Hiro has a vision back in time one year ago to determine what forced Arthur Petrelli to fake his death and create Pinehearst. In the past, Hiro also watches the early days of the Company and how Mr. Petrelli and Mr. Linderman founded it, and their falling out with Angela who saw them as a threat to both Nathan and Peter. Also in the past, Meredith Gordon's origins are shown of how she was captured by Thompson to work for the Company, and of life of crime with her half-brother, whom is the blue-flame fire-starter Flint. Also, Sylar makes a discovery about his powers when he meets Elle for the first time and how she inspired him to kill in order to steal others powers.

Barely escaping from the evil and powerful Arthur Petrelli, Ando forces Hiro to teleport them back to Japan only to discover that Mr. Petrelli has erased most of Hiro's mind and who thinks he's 10-years-old, and still in school. Ando must try find a way to make Hiro remember his powers. Meanwhile, Sylar tries to reason with the captive Elle to force out her anger and to learn how to take her powers without killing her. Mr. Petrelli sends Knox and Flint out after Claire and Peter who try to find a way to outwit their pursuers. Matt Parkman tries to scan the comatose Angela Petrelli's mind to try to save her and learns that Daphne is a double-agent assigned to watch over him and that Mr. Petrelli has something against her. While Suresh continues to unsuccessfully search for the secret to the formula to give people powers, Nathan and Tracy pay a visit to Pinehurst where they meet with the manipulative Arthur Petrelli who offers Nathan the world in exchange for his loyalties and help. Nathan declines, but Tracy, eager to gain more power in politics, accepts.

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.

In Haiti, Peter and the Haitian try to rescue Nathan who has been captured by the sinister Baron Samdei and his militia army. At Pinehurst, Mohinder finds himself a captive by Arthur who wants his powers back for a grand master plan, in which Mohinder attempts to find Maya to ask for help since she may be powerless too. In Kansas, Matt Parkman learns the true nature of Daphne without her super speed, while Ando and an immature Hiro seek answers to their powerlessness in a comic book store in the late Isaac Mendez's '9th Wonders' series detailing their conflict as it happens. In California, the powerless Claire is taken to the hospital dying from her wounds, while Sylar and Elle turn from hunters to the hunted when the vengeful Mr. Bennet attempts to track them down to kill them.

Having traveled back in time 16 years, the immature Hiro seeks out his late mother to try to get his memories back, while Claire has a run-in with a younger Noah Bennett when he was assigned by the company to look after the infant Claire and how she may have become the catalyst for the secret formula. Back in the present, Nathan returns to Pinehurst where Tracy introduces him to a group of U.S. Marines that Arthur has recruited to be his army of super-solders once Mohinder gets the catalyst for the ability-giving formula correct and which hopes the formula will be able to cure his disease... and begin Mr. Petrelli's quest for world domination. Peter and the Hatian return to New York and are sent by Angela in desperate attempt to break into Pinehurst to kill Arthur Petrelli before he can complete the formula. Meanwhile, Ando, Parkman, and Daphne seek out a bicycle messenger who may have the last '9th Wonders' comic book works to learn more about the future and where Hiro is and what to do to save him. Elsewhere, Sylar goes rogue once again by disposing of Elle, and then decides to go after both the heroes and villains to steal their powers for himself.

Under Samuel's guidance, Sylar starts on a path to rediscover his true identity. Hiro helps Emma accept and understand the great possibilities that go along with having an ability. Meanwhile, Peter enlists HRG to help him find a healer who can save Hiro's life.

Under the guidance of Usutu, Hiro has a vision back in time one year ago to determine what forced Arthur Petrelli to fake his death and create Pinehearst. In the past, Hiro also watches the early days of the Company and how Mr. Petrelli and Mr. Linderman founded it, and their falling out with Angela who saw them as a threat to both Nathan and Peter. Also in the past, Meredith Gordon's origins are shown of how she was captured by Thompson to work for the Company, and of life of crime with her half-brother, whom is the blue-flame fire-starter Flint. Also, Sylar makes a discovery about his powers when he meets Elle for the first time and how she inspired him to kill in order to steal others powers.

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.

In flashbacks, we learn what happened to the heroes in the four months after the events at Kirby Plaza. Maja learns of her deadly powers at her brother Alejandro's wedding. Niki starts a Company-sponsored drug program but stops taking the medication only to realize that another hidden personality has emerged. Imprisoned by the Company, Peter Petrelli meets the now familiar Adam Monroe and we learn how he ended up in the shipping container destined for Ireland.

In Haiti, Peter and the Haitian try to rescue Nathan who has been captured by the sinister Baron Samdei and his militia army. At Pinehurst, Mohinder finds himself a captive by Arthur who wants his powers back for a grand master plan, in which Mohinder attempts to find Maya to ask for help since she may be powerless too. In Kansas, Matt Parkman learns the true nature of Daphne without her super speed, while Ando and an immature Hiro seek answers to their powerlessness in a comic book store in the late Isaac Mendez's '9th Wonders' series detailing their conflict as it happens. In California, the powerless Claire is taken to the hospital dying from her wounds, while Sylar and Elle turn from hunters to the hunted when the vengeful Mr. Bennet attempts to track them down to kill them.

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.

Barely escaping from the evil and powerful Arthur Petrelli, Ando forces Hiro to teleport them back to Japan only to discover that Mr. Petrelli has erased most of Hiro's mind and who thinks he's 10-years-old, and still in school. Ando must try find a way to make Hiro remember his powers. Meanwhile, Sylar tries to reason with the captive Elle to force out her anger and to learn how to take her powers without killing her. Mr. Petrelli sends Knox and Flint out after Claire and Peter who try to find a way to outwit their pursuers. Matt Parkman tries to scan the comatose Angela Petrelli's mind to try to save her and learns that Daphne is a double-agent assigned to watch over him and that Mr. Petrelli has something against her. While Suresh continues to unsuccessfully search for the secret to the formula to give people powers, Nathan and Tracy pay a visit to Pinehurst where they meet with the manipulative Arthur Petrelli who offers Nathan the world in exchange for his loyalties and help. Nathan declines, but Tracy, eager to gain more power in politics, accepts.

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.

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.

Having traveled back in time 16 years, the immature Hiro seeks out his late mother to try to get his memories back, while Claire has a run-in with a younger Noah Bennett when he was assigned by the company to look after the infant Claire and how she may have become the catalyst for the secret formula. Back in the present, Nathan returns to Pinehurst where Tracy introduces him to a group of U.S. Marines that Arthur has recruited to be his army of super-solders once Mohinder gets the catalyst for the ability-giving formula correct and which hopes the formula will be able to cure his disease... and begin Mr. Petrelli's quest for world domination. Peter and the Hatian return to New York and are sent by Angela in desperate attempt to break into Pinehurst to kill Arthur Petrelli before he can complete the formula. Meanwhile, Ando, Parkman, and Daphne seek out a bicycle messenger who may have the last '9th Wonders' comic book works to learn more about the future and where Hiro is and what to do to save him. Elsewhere, Sylar goes rogue once again by disposing of Elle, and then decides to go after both the heroes and villains to steal their powers for himself.

Peter Petrelli and Adam Monroe track down another founding member of the Company and learn the location of virus 183. Maya learns how to control her powers but Alejandro' distrust of Sylar leads to a deadly confrontation. Niki returns to New Orleans and tells Micah about her medical condition. When his backpack is stolen, Micah and Monica set off to retrieve it, but things don't work out as planned. Hiro decides to avenge his father's death and goes after Adam. Claire, grieving over her father's death, decides to go public with her powers in a bid to stop the Company.