Claire investigates the sorority attacks, which may have a link to Noah. Elsewhere, Peter finds his job performance improved after gaining a new ability, which also provides a means to help Emma, and Sylar continues his assault on Matt.
When Hiro travels three years into the past, he has a second chance to save Charlie from the hands of Sylar. However, Samuel’s presence serves to complicate Hiro’s mission even further. Elsewhere, H.R.G.’s past with his Primatech partner is revealed.
Matt goes to extreme measures to extinguish Sylar, who continues to torment him. Elsewhere, H.R.G. calls in a favor from Tracy to save a troubled young boy whose misfortunes resemble her own. While Claire and Gretchen are being hazed by their new sorority sisters, they realize pledging might not be their biggest problem.
Samuel guides Sylar on his journey of self-discovery; Hiro helps Emma understand the potential impact of her ability; and Peter asks Noah to help him find someone who can heal Hiro. Ernie Hudson guest stars.
Samuel prepares for new additions to his family, while Lydia warns him of the consequences. Claire discovers that her roommate Gretchen may have a hidden agenda. Meanwhile, Peter finds an unexpected way to connect with Emma, who would prefer to stay distant. Elsewhere, a different side of Sylar emerges as he desperately tries to remember the person he used to be.
Peter faces unexpected consequences for his heroic acts and encounters a reluctant new hero. As Claire continues to adjust to college life, she must figure out how to deal with her ability having been revealed. Meanwhile, Samuel moves heaven and earth to recapture the memories of his late brother Joseph. Elsewhere, Matt struggles with his internal demons as Sylar mysteriously resurfaces.
Peter deals with repercussions from his heroic acts and meets a new woman with abilities (Deanne Bray); Claire deals with the unveiling of her secret; Samuel goes to great lengths to retrieve memories of his brother; and Matt battles inner demons as Sylar reappears.
Angela worries Nathan will discover his real identity; Matt has a surprise visitor; Tracy and Noah team up to investigate a crime; and a friend asks Peter for help.
Claire garners attention at college following an odd death in the fourth-season premiere. Elsewhere, Angela worries Nathan will discover his real identity; Matt has a surprise visitor; Tracy and Noah team up to investigate a crime; and a friend asks Peter for help.
Nathan tries to prevent Sylar from meeting the President. Sylar has his own agenda regarding his partner. Hiro finds there are consequences that come with the return of his powers.