Lumen Pierce has only ever appeared in books.
Lumen Ann Pierce is a fictional character portrayed by Julia Stiles in the Showtime television series Dexter , season 5 . Lumen is introduced in the third episode ( `` Practically Perfect '' ) as a survivor of rapist-serial killer Boyd Fowler . In season 5 , episode 5 , `` First Blood '' , Lumen is revealed to have been beaten and gang raped by a group of men , including Boyd Fowler . She witnesses Dexter Morgan kill Fowler , and thus becomes a key player in Dexter 's life .