Virtually all TV dramas hype their season finales as the “most shocking” and revelatory episode you’ll see. But after last night’s jump-off-the-sofa final scene of Dexter — with the season’s arch-villain, John Lithgow’s Arthur Mitchell, striding into the police station and speaking the words of the episode-title to our anti-hero: “Hello, Dexter Morgan” — the trailer for next week’s season-ender merits a close look itself. I won’t insult you with a spoiler alert: If you don’t want clues about the finale, watch this instead.

So, next Sunday, this:

The trailer hits hard on two key points: That Debra will discover who Dexter’s biological mother was, and (given the moment here when his ghost-stepdad Harry says, “Do you even have a plan here?”) that the family emotions Arthur roils in Dexter could result in a climax that doesn’t just resolve the season-long Trinity plot, but may set in motion some hurried, panicky mistake that could end up harming… Dexter? Deb? Rita?

On a lesser show, constant reminders of how much the protagonist is similar to the antagonist are obvious and irritating. On Dexter, those reminders have come from Dexter himself, in the voiceover narration, and they carry the force of self-discovery. Dexter has been shocked at how, in his effort to become a “normal” person — which in his case means marrying, caring for children, and leading a middle-class existence — normality has proven to contain horrors even a serial killer could not have predicted.

That’s what’s so exhilarating about Dexter this season. The exhaustion of being a good husband, parent, employee, and conducting your secret-life passions: it’s distracting, draining. You make errors. Dexter’s new domesticity has become fraught with unbearable tension. And he has to deal with Lithgow’s Trinity. And, for the first time, guilt over killing innocent people as a result of hasty decisions. Thus the real theme of this season has been “It’s Dexter — he just like us, except with sharper knives!”

Will you be watching the Dexter finale next Sunday?