Season one
Volume 1: Genesis
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.
Season two
Volume 2: Generations
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.
Season three
Volume 3: Villains
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.[14] 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.
Volume 4: Fugitive
The second part of the series titled Fugitives involves what happens after Nathan fails to produce the formula. After the destruction of Primatech and Pinehearst, the Heroes attempt to lead normal lives until Nathan initiates his plan to round up all people with abilities. Meanwhile, Sylar begins the search for his real parents. Throughout the way, the Heroes are guided by Rebel, later revealed to be Micah Sanders. In the finale, Nathan is killed by Sylar in an intense duel. Peter, who steals Sylar's shape-shifting ability in the duel, uses it to disguise himself as the President and tranquilize Sylar. With Sylar's unconscious body and a dead Nathan, Matt is instructed to alter Sylar's mind to believe he is Nathan, with Sylar's acquired ability enabling him to fully embody Nathan's personality and gain his memories.
Season four
Volume 5: Redemption
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".
Webseries
On July 14, 2008 (in between seasons 2 and 3), the first Heroes webseries, Going Postal, was released. The trilogy of online-only videos introduces Echo DeMille, a seemingly ordinary mailman with an extraordinary ability. The three-part series is written and directed by the same creative team behind the main series. On November 10, 2008 (During Season 3), the second Heroes webseries, Destiny, was released. This is the first of many more webisodes sponsored by Sprint. This series is a tetralogy. Destiny introduces Santiago, chosen by the fans. Santiago wonders if his newfound abilities are either a miracle or something else. On the streets of Lima, Peru, he discovers his powers. On December 15, 2008, the third Heroes webseries, The Recruit, was released. The Recruit introduces Rachel Mills, a marine who survives the explosion at Pinehearst. This follows the finale of Volume Three. On December 22, 2008, the fourth Heroes webseries, Hard Knox, was released. Hard Knox flashes back to 18 months ago, to a time when Matt Parkman knew the villain Knox before his abilities began to manifest. It was originally part of the episode "Villains", but was cut due to time constraints. In April, Nowhere Man picks up where the third season leaves off, and focuses on the life of Eric Doyle.On September 28, 2009, Slow Burn began airing along side Season 4 with multiple writers. It showed behind-the-scenes goings-on of the "Sullivan Bros. Carnival" as it follows the character of Lydia, revealing she has a pyrokinetic daughter named Amanda whom she discovers is in trouble and tries to help.