"Dexter" Season Six Poster

Dexter is an American television drama series that centers on Dexter Morgan​ (Michael C. Hall), a bloodstain pattern analyst for the Miami Metro Police Department who moonlights as a serial killer. Dexter structures his killing around "the Code of Harry", a body of ethics and procedures devised by his adoptive father Harry Morgan (who was a Miami cop) to make sure Dexter never gets caught and to ensure that Dexter kills only other killers. Harry also trained Dexter in how to interact convincingly with other people despite his dissociative mental illness, which Harry believed to be sociopathy, arising from Dexter witnessing the brutal murder of his biological mother, Laura Moser.

As an adult, Dexter has largely escaped suspicion (with some exceptions) by being genial and generous and maintaining generally superficial relationships. However, his attachment to his foster (and ultimately adoptive) sister, Debra, his girlfriend (later wife), Rita, his stepchildren, Astor and Cody, and later his biological son, Harrison, have all complicated his double life and made him question his need to kill. Ever since the series' first season, events are set in motion to show the slow but steady humanization of Dexter, progressing further with each season, as Dexter begins to experience a variety of emotions for the first time in years.