When the series finale of Lost aired three years ago with a nonsensical cop-out of an ending that, when you looked a little closer, didn't actually explain a single thing, I was upset. For a few reasons. Of course I was annoyed at J.J. Abrams, Carlton Cuse, and Damon Lindelof for stringing us along all those years and pretending they had a master plan when, it turned out, they were just winging it the whole time. I was also angry at myself, because part of me knew, seasons before, that it was all going to end badly.

That acknowledgment — that I'd led myself down this path to disappointment — actually helped allay some of my finale frustration. It was expected, the signs had been there, I'd just chosen to ignore them. In a larger sense, I really don't understand when people get so viscerally mad about something that happens on TV. It's all a make-'em-up! None of it really happened! And you chose to watch whatever it is you're furious at. No one forced you. It seems silly to get angry. So imagine my surprise, then, when last night's Dexter series finale made me so angry that I almost threw something at the TV.

Unlike Lost, it was hard to tell how Dexter would end. Not in terms of plot, but in terms of quality. Lost was pretty much a steady downward line from season one to the bitter end, whereas Dexter has veered wildly from terrible to terrific, sometimes within seasons. Yes, the last truly great season of this weird and uneven show was season four, when Dexter squared off against the Trinity Killer, with tragic consequences. But there have been genuine moments of greatness since then, so I don't think any of us were foolish to expect, or at least hope for, a real wham-bang finish. But what we got instead was, frankly, awful. Needlessly depressing and completely evasive, the Dexter series finale was one of the worst endings to a television show I've ever seen.

Read no further if you don't want spoilers.

First off, Deb. Dear god what did they do to poor Deb. She was shot in the penultimate episode, but for most of the finale she seemed like she was going to recover. But then nope, she had a stroke and was basically a vegetable and so Dexter pulled the plug and tossed her into the sea. Why? To what end? So Dexter could feel the ultimate guilt? Maybe, but mostly I think they thought it would be cool and poetic in some vague way to have Dexter dispose of his sister's body like so many of his victims. That seems like the only real, concrete reason why the writers decided to kill the show's only likable character — a stylistic flourish that dragged the episode to the depths of senseless downer-dom. Jennifer Carpenter, one of the sharpest and nimblest actors on television these days, deserved much better. So did we. Why did Deb die?? Deb did not have to die. Especially like that.

In a broader sense, the Dexter finale copped out in the worst way possible. The central tension of this show has, of course, always been the nature of Dexter's secret life. Will he get found out? Will he go to jail? Be killed? What? The promise of Dexter was that we would get some kind of payoff, or resolution, or something. What we did not expect, and were not promised, was Dexter driving into a hokey CGI hurricane and then reappearing as some sort of bearded fisherman in the show's final shot. Seriously, that's what happened, Hannah and Harrison off in Buenos Aires, Deb dead, the Miami metro squad completely unaware of Dexter's dark proclivities, and Dexter with a beard and a sinister look. After all that, the writers' solution was just to have Dexter fake his own death and run away? How dumb, how lazy. "All that stuff about his loyalty to the squad and his sister and his freaking son? Nah, doesn't matter. He just runs away at the end."

It feels like all the progress we watched Dexter make, in lurching fits and starts, over the course of this show's eight seasons was all for nothing. There was a way to end this show on a depressing note without tossing everything out. I'm not saying that the ending had to be sunshiny and neatly buttoned up. But arbitrarily killing Deb and sending Dexter off to be a fisherman? That's a hasty dodge, a sort of "They were all in purgatory I guess? But only for the last season?" kind of a thing that is, in its own silly way, downright embarrassing. And I'm angry about it!

Angry that I stuck with this show even through the stupidity that was Lumen, that was Miguel Prado, that was Colin Hanks and his imaginary Edward James Olmos. There have been myriad plot stumbles on Dexter over the years, but it always teased something coming down the road that made me stick around. I suppose my devotion really was just an unyielding curiosity about how it would all end, so to wait all that time, slog through all that dull stuff, just to arrive at this slipshod, out-of-nowhere conclusion? Yes, it makes a person angry, even though being mad at television is a pretty silly, pointless activity. It feels like Dexter violated a trust or something, that it didn't even have the care to put together something nice for the devoted fans who loyally suffered through Stan Liddy disappointments and, y'know, the entirety of Angel's character. Isn't that mean? To treat people like that? it felt pretty mean last night.

It's a shame to feel this way about Dexter, or anything you've spent so much time with. When people ask me if they should watch Lost from the very beginning, thinking it might be some fun new project, I sigh and tell them no. Ultimately the first three captivating seasons aren't worth what comes after. And I'm afraid I'll say the same thing about Dexter, a show whose unbelievably unsatisfying end ruins all that came before it. All that shock and excitement when Deb learned Dexter's secret, when she pulled that trigger on LaGuerta, when Dexter found out he was having a kid, when Rita died, when he showed any glimmer of humanity. It all ended up at the bottom of the ocean. That's all. What a waste of time! Dexter was plenty entertaining at its peak (it was never Great television, but it was definitely good), a suspenseful and intricate thriller that rewarded loyal viewing with frequent callbacks and recurring characters, but as a show about one man's grand and elaborate lie, it needed to nail the landing in order to really succeed. And it tumbled hard. And thus the whole thing was for naught. Turns out, the show's final victim was itself.