Double-length episode. Claire starts as a freshman in college, but cannot fully leave her old life behind. Peter returns to his job as a paramedic, saving people with the help of Mohinder's abilities. Hiro and Ando have started a "Dial a Hero" business, but Hiro is not in control of his power and believes himself to be dying. Angela is worried about Nathan, who is starting to display Sylar's abilities. Samuel, Lydia and Edgar use their abilities to find other Heroes. Tracy continues to hunt down former Building 26 employees, including Noah and Danko. Sylar's consciousness manifests itself inside Matt's mind.

Samuel attempts to manipulate Peter into filling his brother's position at the carnival. While facing the consequences of this, Peter meets a reluctant new hero. Claire tries to adjust to college life and the revelation of her ability. Sylar uses Matt's ability against him in a bid to return to his body.

Hiro distracts himself by helping others, and in the process learns to accept his own situation. Angela helps Nathan remember his past, but instead uncovers a long-buried secret. Tracy seeks out her old job but wants to do more to help people. Noah begins to drift back to his old life.

Sylar wakes up with no memories. Claire discovers that there is more to her new roommate than what she already knows. Peter helps Emma to better understand her ability. Samuel seeks out a new member to the carnival family.

Sylar starts his journey to rediscover himself with the help of Samuel. Hiro shows Emma how to accept her ability and the possibilities it brings. Peter enlists Noah's help in finding a healer to save Hiro.

Matt looks for a way to get rid of Sylar after he learns to take control of his body. Noah enlists the help of Tracy in order to help free Jeremy from the police. Claire is concerned that someone wants to eliminate Gretchen during a treasure hunt for their sorority.

Hiro travels three years into the past to save Charlie's life from the hands of Sylar, only to have things complicated by Samuel's presence. Meanwhile something from Noah's past is revealed.

Though Peter's new ability is helpful in his job, it is trying on him until he uses it to help Emma. Claire learns that the sorority rush attack happened because of something her father did. Sylar's battle to control Matt's body moves into dangerous territory.

Mohinder discovered something shocking on an old film reel nine weeks ago. Hiro travels back in time to retrieve that film for Samuel. Tracy begins to lose control of her ability. Nathan and Peter go to Matt, only to discover the truth about Sylar.

Three Thanksgiving dinners. The Petrellis: Nathan and Peter confront Angela about the truth with disastrous consequences. The Bennets: a dinner full of drama between Claire and Noah. The Carnival Folk: Hiro travels back in time with Lydia to discover the truth about Joseph's death while Samuel learns of the full potential of his ability.

Claire travels to the carnival and finds an open invitation. Noah confesses the truth to Lauren about their past relationship. Peter uses the Haitian's ability to get rid of Sylar and bring back Nathan, but must deal with an unexpected choice by Nathan.

Claire searches for answers as she is suspicious of Samuel's true motives. Samuel seeks out Emma in hopes she can help him find someone. Hiro seeks out Ando for his assistance on a new mission but has trouble communicating his intentions.

Peter has trouble coping with Nathan's death as Claire tries to console him. Sylar returns to the Carnival to kill Samuel, only to discover something unexpected. Edgar and Noah team up to find a way of bringing down Samuel.

Hiro and Ando travel to Florida to rescue Mohinder from a mental institution. Noah seeks out Matt to help him with a lead on dealing with Samuel. Peter learns about a horrifying potential future event involving Emma.

Hiro falls into a tumor-induced hallucination in which he goes on a trial of his life for changing the past. Sylar confronts Claire in hope that she will help him figure out the truth behind his problems. Samuel tries to woo his old love Vanessa with disastrous consequences.

Peter pursues a way of keeping his dream of Emma from coming true. Sylar seeks out Matt in hopes Matt will help remove his powers. Claire tries to negotiate the surrender of Samuel to Noah. Peter enters Sylar's mind.

Peter tries to help Sylar free himself from his own nightmare. Samuel tries to convince Claire to join his family by revealing dark secrets from Noah's past to her. Lauren confronts Samuel at the carnival. Samuel makes preparations for their final "performance" in New York.

Samuel's ultimate plan takes effect as Emma is forced into using her abilities to help him kill thousands of people, only to have an unlikely pair of heroes come to her rescue. Noah seeks Claire's forgiveness as they work to escape from their underground prison. Hiro comes to acceptance over his past decisions as he is reunited with his long lost love and seeks to avert disaster. Claire shows the world the truth it may not be ready for.