Lumen Pierce is a character from Dexter.
The fifth season of Dexter premiered on September 26 , 2010 , and consisted of 12 episodes . The season focuses on how Dexter comes to terms with the aftermath of the Season 4 finale , stopping a group of serial rapists and avoiding a corrupt cop who learns his deadly secret . Lumen Pierce . She remains for the rest of the season , and leaves following the season 5 finale , `` The Big One '' . `` The Big One '' is the fifth season finale of the American television drama series Dexter , and the 60th overall episode of the show . In the episode , Dexter attempts to save Lumen from Jordan Chase , as his sister , Debra , comes closer to uncovering the truth in her investigation . It marked the conclusion of the season-long subplot pertaining to Lumen seeking revenge against Jordan Chase , and marked the last in a string of regular guest appearances by Julia Stiles and Jonny Lee Miller , who played Lumen and Chase , respectively .