Peter and Caitlin learn about the endstage effects of the Heroes virus. Many of the Heroes work together to fight the Nightmare Man. West is shocked to the identity of Claire's father. Hiro and Kensei's journey comes to an end.

Peter travels to Primatech in Texas to destroy the virus, but not everything is what it seems. Hiro continues the pursuit of his father's killer, while Matt pursues the last Company member in the photo. Nikki is reunited with Micah but has bad news, while Maya has to choose to remain with Alejandro, or go with Sylar.