The endgame has a different importance, though, in “Dexter,” a more stylized and fanciful show with an even more single-minded focus on its protagonist’s psyche. The question of Dexter’s fate was baked into the gothic premise: a psychopath trained by his adoptive father, a police officer, to be an honorable killer, dispatching only those who needed killing. And the show’s mix of film noir and fairy tale seemed to leave open the possibility of redemption, and even a happy ending.

The result is that, for at least two and perhaps three seasons, it has felt as if we’d been in a long process of preparation for Sunday night, with story lines whose primary purpose was to push Dexter ever closer to an edge that kept receding as the show’s ratings remained strong by premium-cable standards. (Seasons 7 and 8 have been the show’s highest-rated, averaging 2.1 million to 2.2 million viewers.)

It has been a frustrating ride for those of us who loved the show’s early seasons, when it achieved an unusually happy balance of interesting long arc (Dexter’s progress toward humanity and his intense relationship with his foster sister, the dedicated cop Deb) and snappy, short-term storytelling (his season-length battles with other serial killers and his dealings with his droll colleagues in the homicide squad of the Miami police).

In addition to gore, suspense and heartbreak — including the authentically shocking murder of Dexter’s wife at the end of Season 4 — “Dexter” was also marked by its easygoing, sunny vibe and its undercurrent of jabbing workplace humor. As the rest of the cable drama landscape grew increasingly grim and heavy-handed, it was a welcome respite, like picking up a fast and punchy Charles Willeford novel (“Miami Blues,” say) after slogging through a well-reviewed pretentious literary mystery.

Even as the story has lost some of its steam in recent seasons, it’s been worth staying around because of the cast, beginning with Michael C. Hall and Jennifer Carpenter, as Dexter and Deb, and including excellent supporting performances by David Zayas, C. S. Lee and Desmond Harrington, as cops who never quite figure out that their blood-spatter analyst is murdering people under their noses.