Common people discover that they have super powers. Their lives intertwine as a devastating event must be prevented.

Season 2 introduces new stories — and new heroes — following the apocalyptic showdown in New York City. Claire has moved with her family to Southern California in order to hide her indestructible abilities and there she encounters a young man with a secret of his own. Matt gains new authority in tracking down a murderous force stalking the Heroes, while Suresh uncovers a virus that could eradicate them all. As each sensational chapter unfolds, there is no resisting the extraordinary.

Season 4 begins with our heroes putting their lives back together. Claire finds that her biggest challenge is forgetting her old life and starting college. Hiro Nakamura goes back to his old life in Japan, but discovers that he has a terminal illness and sets out to fulfill his own personal bucket-list. Peter Petrelli returns to work as an ordinary New York City EMT. H.R.G. is adjusting to life as a single man, but when Mohinder Suresh offers H.R.G. compelling evidence of a new danger, it makes H.R.G. wonder if he should get back in the game. Nathan Petrelli returns to the Senate and begins to notice strange changes in himself. Matt Parkman returns to life as an ordinary family man, but finds something unfamiliar buried deep within his psyche. And a strange and dangerous carnival comprised of a traveling band of outsiders with powerful abilities suddenly poses a grave challenge.

After being murdered by corrupt colleagues in a covert government agency, Al Simmons makes a pact with the devil to be resurrected to see his beloved wife Wanda. In exchange for his return to Earth, Simmons agrees to lead Hell's Army in the destruction of mankind.