Usually, when a beloved series approaches its end, there’s a feeling of wistful anticipation at the prospect of resolving loose ends and saying goodbye to something special.

I said usually, however, and the finale of “Game of Thrones” is the exception. I’m as curious as anyone to know who ends up sitting on the Iron Throne. But I’m also worried that showrunners David Benioff and D.B. Weiss are going to botch the landing in King’s Landing – or rather, that they already have.

As the HBO series has moved beyond the incredibly intricate material of George R.R. Martin’s unfinished series of fantasy novels, the visuals have gotten better and better, while the characterization and plotting have gotten worse and worse.

Characters do things, not because that’s just what they would do in a given situation, but because the chess pieces need to move toward the next dazzling display of battle choreography. You can blame Benioff and Weiss, who clearly seem bored, and eager to move on to other things. They can get away with this only because the writers, at this point, are essentially working from Cliffs Notes: They know what the endpoint is, but lack Martin’s deft plotting to get the story there.

Which raises the question: Why has the series outraced the novels? “A Dance with Dragons,” the most recent release in Martin’s “A Song of Ice and Fire” series, came out in 2011, shortly after the HBO series started. With two entries remaining in the planned seven-book series, Martin has had eight years to move the plot forward, but he hasn’t. Many of his fans, including me, have become grimly convinced he never will.

If you’ll allow me a bit of speculation, I’ll suggest that that’s because Martin set himself a basically impossible task, tearing down the treacly conventions of the fantasy epic, while keeping the magic, the royalty, the swordplay and the world-in-balance existential conflict. One hesitates to say that a book with dragons and blood magic can paint the world as it really is, but Martin did create a world that felt much more plausible than your typical ethereal fairy epic.

Main characters die, horribly, often as a direct result of their noblest gestures. When they’re not dying, they’re suffering in myriad and inventive ways. And that was a great part of the appeal, because there’s so much more suspense when you know, as real people do, that any given battle could end with the hero’s entrails spilled.

But in a real pre-modern world, where long journeys can stretch into years, it is immensely difficult to make two characters arrive in the same far-flung locale at once. That meant that at any given time, many of Martin’s viewpoint characters (24 of them, by my count) were at loose ends, either traveling or waiting for someone else to show up. It’s admirable that Martin tried to give them something to do in the interim, so readers wouldn’t lose track of important characters, but many of those plots were – again, realism – not very interesting.

In trying to create a world where anything could happen to anyone at any time, he may also have created expectations that could never be fulfilled. We loved surprises such as the carnage of the Red Wedding, because that made the whole thing more believable. But in the end, a good story must deliver something that reality rarely does: a clean narrative arc.

Which meant that despite the illusion that anything could happen, most plausible things actually couldn’t. One way or another, the Starks had to win the battle for humanity, and Westeros, because otherwise why did we spend all those years following them around? Making that feel realistic in a world that isn’t governed by cosmic justice is, well, a heroic task.

Martin, having reached the point in the series where he needs to steer the characters toward their denouement, seems to have become overwhelmed by the magnitude of the job he set himself. And the lesser talents of Benioff and Weiss certainly weren’t up to it, which is presumably why they dispensed with plausibility and just gave us lots of CGI dragons.

And so I’ll be going into Sunday night with a very different sort of wistfulness than I would have expected a few years back: a lingering sadness that the very things that made me love “Game of Thrones” have made a satisfying resolution so very unlikely.

Read more: