The fourth season of Heroes began airing Monday, September 21, 2009, with Volume Five: Redemption. Volume Five begins with the introduction of Samuel, a leader of a carnival consisting of evolved humans, who are tracking down future members with abilities of their own. In addition, Sylar's transformation into the deceased Nathan affects the lives of the Petrelli family, as well as those surrounding them.

The third season of Heroes began airing Monday, September 22, 2008, beginning with Volume Three: Villains and concluding with Volume Four: Fugitives, ending on April 27, 2009. Volume Three begins with the assassination attempt on Nathan, and the consequences it has in the future. In addition, several villains escape from the confines of Level 5, and the Company attempts to recapture them. Volume Four starts with Nathan telling the President about the existence of evolved humans and the hunt for said humans ensues.

The second season of Heroes begins four months after the conclusion of Volume One. The events of Kirby Plaza have changed the lives of the Volume One survivors, and not necessarily for the better. Meanwhile, several new characters are introduced, and the origin of the Company begins to be revealed, as its founders are faced with a mysterious figure from the past determined to kill them off. Eventually, an even bigger threat occurs: a virus, threatening to kill 93% of the world's population.