Plot hole: If Noah could be brought back from the dead with Claire's blood why couldn't they bring back Nathan? Was turning Sylar into Nathan really the first thing they could think of?
Seven Minutes to Midnight - S1-E8
Continuity mistake: When Mohinder is back in India, his mother tells him that his sister Shanti died at the age of 5, when Mohinder himself was 2. In "The Hard Part", Mohinder tells Molly Walker that Shanti died before he was born, and shows her a photo of Shanti (who looks 5 years old) and his pregnant mother.
Continuity mistake: When Matt Parkman gets thrown out of a window by Niki Sanders, he lands at least a few stories down and has a cut upon his head. The amount of blood on his head differs significantly from shot to shot.
(Volume Two: Generations) Four Months Later... - S2-E1
Continuity mistake: When Claire hugs Mr. Bennet she is holding her note in her right hand. In the next shot as she turns around and runs off to school the note is in her left hand.
Revealing mistake: The money that Micah dumps out of his backpack is very obviously fake. In fact, the $20 bills have Benjamin Franklin's portrait on them.
Other mistake: When they show the comic book and Hiro looks up the artist's address, it is listed as 215 Reed St. 7. The door to the artist's loft says his address is 681. (00:01:10)
Visible crew/equipment: When Claire runs away from Bob after he calls her "Ms. Bennet", you can see Bob's shadow and another person's shadow on the ground. Since no one else was standing next to them, it has to be a crew member, most likely a camera man based on the odd shape of the shadow.
Continuity mistake: When Charlie invites Hiro over to help celebrate her birthday, the invite is almost immediately after she says "hold that thought" and walks away from his booth. But in that scene in the previous episode, Charlie was already across the room with the other townspeople when she signaled Hiro to come over.
Continuity mistake: After throwing the laptop, when Mohinder takes the key out of the book, the tape is bunched up and stuck to the key, but in the next shot the tape is fresh and sticking out freely.
Continuity mistake: Maya's necklace disappears between shots when she accuses Sylar of killing her brother.
Continuity mistake: When Alejandro finds Maya outside the tunnel, she has black ooze from her eyes running down her cheeks. As he starts his healing, we get a close-up shot of how the ooze fades and disappears from Maya's face. But in the next shot of her face, when she falls forward, the black stuff is back on her cheeks. It's gone again in the next shot of her. (00:29:20)
Continuity mistake: When Meredith and Nathan are talking in her trailer, as he says, "I could have been a much better person back then", he has his sunglasses in his hand and places that hand on the table. Cut to a shot from behind him, and his hand is resting on the table with the sunglasses beside it, with no time to put them down and move his hand in between the shots. Also, when Meredith says, "You and me, we were never gonna work out", his hand goes from being on the table to his lap between shots, once again without having had the time to move it. (00:32:10)
(Volume Two: Generations) Four Months Later... - S2-E1
Visible crew/equipment: S02E01 "Four Months Later". As the samurai warriors are about to engage the attack, a close-up shot of Hiro turning around reveals the white screen reflected in his glasses.
How to Stop an Exploding Man - S1-E23
Continuity mistake: Hiro's sword changes position between the shot in which Hiro arrives to the scene and the shot when he is about to kill Sylar.
Continuity mistake: Right before Sylar shoot Maya, you can see she already has a bullet wound on her chest.
Continuity mistake: When Peter is having his vision of New York, D.L. can be seen picking up Micah and running away. When the camera pans out to show Matt holding them back, D.L. is picking up Micah again.
Factual error: In Season 2, Episode 3, Peter and the Irish family rob the bookmakers and the security guards shoot at them. In Ireland, even the police don't carry weapons. Let alone security guards.
Continuity mistake: At the end of ep. 1-14, "Distractions", Meredith calls Nathan to tell him about Claire. In that episode he is holding the phone to his ear, with nothing else in it. In the beginning of this episode, when the same conversation is shown, he is holding a pen in the same hand as the phone. Also, in ep. 14 Meredith said to him, "We haven't spoken in a long time, but... Our daughter just found me". In this episode, she says, "We haven't spoken in a long time, but I just had... Our daughter just found me".
Continuity mistake: When Maya is arrested, she starts manifesting her powers on the policeman. In a close-up, we can see the black ooze coming out of her eyes. Cut to a shot from above, when the policeman's eyes turn black and he drops the handcuffs, and Maya's cheeks are suddenly clean again, with no trace of the black stuff. (00:33:45)
Visible crew/equipment: When Mohinder, Sylar, Maya and Molly are at Isaac's old flat (now Mohinder's lab), as Mohinder and Sylar walk down the stairs, you can see the moving camera crane reflected in the glass behind them.
Chosen answer: It's not been made 100% clear. It was originally assumed that he actually consumed part of the brain, but this has turned out not to be the case. Sylar has been shown all along to have an instinctive knowledge of how things work and how to fix them - this is his actual original power and the ability that made him an exceptional watchmaker and repairer. It appears that he uses a similar process when acquiring new powers - he exposes the brain of the target, allowing him to examine it and determine how their power functions. He can then apply that knowledge to his own brain, allowing him to replicate the ability in question.
Tailkinker ★