The fifth season sees Dexter facing a new challenge in the form of Arthur Mitchell (played by Jeffrey Dean Morgan), a serial killer known as "The Trinity Killer." Arthur's actions lead Dexter to question his own morality and the code he lives by. Meanwhile, Debra and Lila team up to uncover the truth about Dexter.
"The Trickster" (Episode 1), "The D.O.S.S." (Episode 6)
The first season introduces us to Dexter Morgan, a forensic analyst for the Miami-Dade Police Department. After his father's death, Dexter's adoptive father, Harry Morgan (played by James Remar), reveals to Dexter that he is a serial killer and teaches him the "code" - a set of rules that govern his killing behavior. The season focuses on the "Ice Truck Killer" (played by John Lithgow), who is targeting young women and leaving their bodies in ice-filled trucks.
