He reappears in the following episode "Salvation" first seen making out with Thea at his house.

He would reappear in the following episode, as the same character.

George's philosophy of doing the opposite to his natural instincts reappears in the episode "The Opposite".

Libby briefly reappeared in the 2008 episode "Meet Kevin Johnson".

She reappears in the episode "Out From the Past".

He reappears in the fifth episode, having been turned into the evil Black Knight.

Boone reappears in the final episode of Lost.

Karl reappears in the second episode of the fifth season, where he was asked by Julie to pick up and help her with her insurance.

He reappears sometimes later in the episode.

Aya reappears in the episode using a number of flashbacks from the series and in new scenes.