Dexter's Lumen was introduced as an intriguing new character in season 5 before making a surprising exit at the end of the season. Dexter deals with the titular Dexter Morgan, a vigilante-type serial killer who also works for the Miami Metro Police Department as a blood-spatter analyst. Over 8 seasons, Dexter followed a strict code given by his police officer father to only kill other murderers that deserve it, evade getting caught, and avoid emotional attachment with victims - a rule he broke through his intimate involvement with Lumen.

Julia Stiles signed on to Dexter in season 5 as Lumen, a role that earned her Emmy and Golden Globe nominations. The addition of Lumen also came in the first season after Dexter's wife Rita was shockingly killed in the season 4 finale. In many ways, Lumen felt like a perfect character to fill that role in Dexter's life. That made it all the...