Season 2 depicts the different approaches to the fight for mutant civil rights that are taken by the Mutant Underground and the Hellfire Club, and also introduces the Morlocks and further explores the Purifiers—all groups originating in the comics.

A suburban couple's ordinary lives are rocked by the sudden discovery that their children possess mutant powers. Forced to go on the run from a hostile government, the family joins up with an underground network of mutants and must fight to survive.

A re-imagining of the 1980s miniseries about the world's first encounter with an alien race in which the aliens call themselves The Visitors, and have a seemingly friendly agenda that may or may not be a cover for something more malevolent.

4400 centers on the return of 4400 people who, previously presumed dead or reported missing, reappear on Earth. Though they have not aged physically, some of them seem to have deeper alterations ranging from superhuman strength to an unexplained healing touch. A government agency is formed to track the 4400 people after one of them commits a murder.

Two teenage boys secretly meet up in a cabin, bear witness to a shooting and barely escape with their lives. Desperate to keep their relationship a secret and in fear of being found by the perpetrator, they remain silent but soon learn that what has been seen cannot be unseen -- and when you witness a horrible event, it changes everything.