Trapped and terrified, Nathan and Tracy fight for their lives against a much-changed monstrous Suresh. Meanwhile, Elle returns with a shock for Claire and her family.
To prepare for the confrontation ahead, Hiro follows respected businessman Arthur Petrelli in the days before he 'died' to discover what drove him to create rival company Pinehearst and strike at Angela.
Peter and Matt are thrown into unexpected, uncharted territory. Meanwhile, in Tokyo, Hiro and Ando are charged with safeguarding a family secret that could split the planet apart.
Seeing a future where nearly everyone has abilities - a world destined for destruction - Peter resolves to prevent this earth-shattering end, whatever the cost.
Armed with H.R.G.'s old files and a taser, Claire attempts to take down her first target: Stephen Canfield - a Level 5 escapee with the ability to create black holes - unaware that others are closing in.
Deep below Primatech Paper, Peter's reunion with Nathan turns violent when the brothers Matt and Hiro all clash thanks to Adam and his pursuit of the deadly Shanti Virus.
Nathan's determination to save a comatose Peter forces him to turn to Simone for help. Isaac's puzzling "Hiro vs. T-Rex" painting inspires Hiro and Ando to search for the pictured samurai sword.
Chased by unknown assailants, Hiro's search for the sword takes a turn when his father appears. Meanwhile, a cleaned-up Isaac dedicates himself to stopping New York's destruction.
After reuniting Sylar and Elle, Arthur orders them to find Claire and bring her to him. Meanwhile, Nathan and Peter Petrelli travel together to Haiti in search of the only man that can stop their father from destroying the world.
In the aftermath of the showdown against Arthur Petrelli, the Petrelli brothers find themselves battling against one another. Nathan makes a move that will have global repercussions.
Samuel prepares for new additions to his family, while Lydia warns him of the consequences. Meanwhile, Claire discovers that her roommate Gretchen may have a hidden agenda.
A restored Sylar seeks out the carnival to obtain a new batch of powers, but discovers a new weakness. Meanwhile, Claire and Peter try to resolve their emotions at Nathan's wake.
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.
The new and different Sylar pays Matt a visit, while Peter tries to warn Emma that Samuel isn't what he seems. Meanwhile, Noah begins his plan to infiltrate the carnival and capture Samuel.
Sylar visits Claire, while Hiro's past decisions manifest subconsciously due to his brain tumour. Meanwhile, Samuel tries to impress Vanessa, his long-lost love, but things don't go as planned.
With the election and NYC's destruction looming, Nathan has a disturbing face-to-face meeting with the shadowy Linderman. Meanwhile, Hiro's attempt to steal the sword steers him in a grim new direction.
In Las Vegas, Hiro's plan backfires when he cautiously turns time to his advantage at the gambling tables. Meanwhile, Claire's uncanny healing abilities are put to the ultimate test.
While Hiro convinces his friend that they are destined to travel to America to save the world, a frightened Niki follows instructions from a mysterious, unknown source that directs her to the middle of the desert.
As people around the world find their lives disrupted by their new extraordinary abilities, authorities investigate several bizarre and gruesome murders.
As a total eclipse casts its shadow across the globe, a genetics professor in India is led by his father's disappearance to uncover a secret theory - that there are people with superpowers living among us.
Facing a crisis involving her son Micah, a distraught Niki reveals her personal struggles to a friend. Pushing aside his own issues at home, Matt assists Audrey's investigation into another bizarre murder.