The plot of Heroes is designed to be similar to the stories of comic books with small story arcs built into the series' overall large story arc plot. Each season of Heroes is designed to involve ordinary people who discover extraordinary powers, and how these abilities take effect in the character's lives.
On May 4, 2009, NBC confirmed renewal of Heroes for a fourth season consisting of 18 to 20 episodes. The season began with a 2 hour premiere on September 21, 2009. The fourth season contains volume five, Redemption. Madeline Zima joined the cast as Gretchen, Claire's new friend in college. Rick Worthy will have a recurring role, playing Matt's new police partner, an experienced and capable Los Angeles cop. Robert Knepper joins the cast as Samuel, a new villain. Ray Park has reportedly also been cast "for a sizeable arc
Season three featured 25 episodes that aired beginning on September 22, 2008. The season comprised volumes three and four, titled Villains and Fugitives respectively. The lead-in to Villains showed Sylar regaining his lost powers, shown as the final scene of the Generations finale. Tim Kring said that the new volume would bring a cadre of villains to the show, hence the title. Volume three began with the assassination attempt on Nathan Petrelli, and the consequences it has. In addition, several villains escape from the confines of Level 5, and the Company attempts to recapture them. Arthur Petrelli heals from systemic nerve damage with the help of Adam Monroe's healing abilities and eventually recruits a few of the villains (Flint Gordon Jr., Knox, and Daphne Millbrook) while later luring in Mohinder Suresh, Nathan Petrelli, Tracy Strauss, Elle Bishop, and Sylar. Their objective is to create a formula to give people abilities but after many failures they soon realize they need to find the "catalyst", which is contained within a person.
The second part of the series titled Fugitives involves what happens after Nathan fails to produce the formula. The main plot is that Nathan forms his own company with the direct purpose of tracking down and locking away those people with abilities. This includes Peter who refuses Nathan's offer of protection.
Season two featured volume two, Generations, and began on September 24, 2007. Volume two begins four months after the events of Kirby Plaza. The main plot arc of Generations deals with the Company and its research on the Shanti virus. This research is explored through the Company's founders, whose identities are revealed, as well as through the effects of various strains of the virus. The "heroes" ultimately come together in an attempt to stop the release of a deadly strain of the virus and avert a global pandemic.
Isaac's painting of New York's destruction in "Genesis" - the following episode, set five weeks in the future, depicts the same explosion, and the painting forms the basis of the primary story arc of the first season.
Season one featured 23 episodes that were broadcast starting September 25, 2006 collectively as volume one, Genesis. The series went on hiatus twice; first from December 4, 2006 to January 22, 2007, and again from March 5 to April 23, 2007, with the season finale airing on May 21, 2007. The volume begins as a seemingly ordinary group of people gradually become aware that they have special abilities. Events illustrate their reactions to these powers, and how the discovery affects their personal and professional lives. At the same time, several ordinary individuals are investigating the origins and extent of these abilities. Mohinder Suresh, a geneticist, continues his late father's research into the biological source of the change, while Noah Bennet represents a secret organization known only as "The Company". While coping with these new abilities, each of the characters is drawn, willingly or unwillingly, into the Company's conspiracy to control superpowered people and into a race to stop an explosion from destroying New York City.