(This post is all spoilers about the “Sharp Objects” series finale.)

As the minutes ticked by toward the end of HBO’s “Sharp Objects” series finale on Sunday night, readers of Gillian Flynn’s novel may have found themselves thinking, “So . . . when are they going to get to the twist?”

After all, in the book, the big reveal wasn’t only that “Munchausen mom” Adora (Patricia Clarkson) had been poisoning her children, and was responsible for the death of her daughter, Marian. The other grisly twist was the identity of the killer, the show’s big mystery: Who murdered 10-year-olds Ann Nash and Natalie Keene and removed their teeth?

The killer wasn’t Adora, even though she was charged with the crime — police found a pair of pliers in her house, and they matched the marks on Natalie and Ann’s gums.

Adora (Patricia Clarkson) with her tray of supplies. (Anne Marie Fox/HBO)

However, the pliers belonged to Amma (Eliza Scanlen), Adora’s precocious teenage daughter and Camille’s (Amy Adams) half-sister. Amma murdered both girls because . . . well, viewers never found out. Amma essentially confessed, and the show immediately ended. No explanation. It was infuriating and confusing all at once.

Viewers knew something was up in the last few minutes of the episode. After their mother was sent to jail, Amma went to live with Camille in St. Louis. Things started out okay — Camille’s boss, Curry (Miguel Sandoval), even commented on how well Amma was adjusting, considering that she was coming from a house where her own mother routinely made her sick.

But alarm bells started going off during a dinner at Curry’s house with Camille, Amma and Amma’s new friend, Mae (Iyana Halley). Amma looked irritated when Mae impressed the adults by saying she enjoyed reading newspaper editorials.

Then a couple of scenes later, Mae’s mother showed up at Camille’s door looking for her daughter. When Camille said the girls went to the park, Mae’s mother revealed that Amma and Mae “had their first little fight,” and it was probably over a boy or something frivolous.

Uh-oh. Camille knew her twisted half-sister better than that. Mae’s mother left, and Camille went to Amma’s dollhouse, which she had been creepily fixated on the whole season. When Camille took a closer look, she realized one of the bedroom floors was made of teeth. Obviously, the ones that belonged to Natalie and Ann.

Eliza Scanlen stars as Amma Crellin in the finale of “Sharp Objects.” (Anne Marie Fox/HBO)

Camille looked horrified, with an expression that will certainly help earn Adams a richly deserved Emmy award. Amma suddenly appeared behind her. And she knew that Camille knew.

“Don’t tell mama,” Amma said.

That’s it! Cut to black. Show’s over. Sorry, folks, have fun figuring that one out.

If you stuck through the credits, you got a couple more details. Or at least, quick shots of Amma and her friends pinning down Ann and Natalie to kill them. And in the very last scene, a brief image of Amma in a white dress walking into the woods. (In the second episode, a young boy told police a “woman in white” took Natalie.)

It’s a classic and frustrating TV trick to abruptly end a show and leave the audience to interpret what they just saw. But in this case, it felt as if there were simply too many big questions left. How did Amma involve her friends in the murders? How did she pry out the teeth, when the show made sure to emphasize that it would take a very strong person to do so? Is the assumption that Amma killed Mae, as well? Most importantly: Why did she kill them?!

Flynn’s book offers a few pages of answers, including the fact that Amma winds up in a juvenile detention facility. And, yes, she did kill her new friend. Camille ultimately considers their mother, Adora, at fault for Amma’s actions.

“Amma controlled Adora by letting Adora sicken her. In return she demanded uncontested love and loyalty,” Camille explains. (Apparently, Amma was jealous because Adora spent time tutoring Ann and Natalie.) “You can come up with four thousand other guesses, of course, about why Amma did it. In the end, the fact remains: Amma enjoyed hurting. I like violence, she’d shrieked at me. I blame my mother. A child weaned on poison considers harm a comfort.”

Can viewers still enjoy the show without knowing that information? Sure — plenty did. Although it’s likely that others were confused and would have liked some closure after sitting through eight hours of a miniseries.

Obviously, every post-show interview with the creators and writers asked about the shocking ending. They all had different a reasoning:

Director Jean-Marc Vallée to Vulture: “The whole series was designed through Camille’s perspective. So she’s the one discovering the teeth and the floor made out of teeth. We’re with her and she sees Amma arriving, so of course, she wasn’t there when Amma killed the girls. That didn’t make sense to cut to these images from Camille’s perspective, and it didn’t make sense to cut suddenly to Amma because, of course, Amma is not thinking about, Oh, let me think about how I killed this girl. It wasn’t good storytelling, you know?”

Flynn, also a writer on the show, to Entertainment Weekly: “It was a really tricky balance because what feels correct in the book doesn’t always have the same balance on the screen — you can explain more on the page and get away with it. There was worry that having Amma talking too much with Camille was going to feel too explanatory and too expository.”

Series creator Marti Noxon to The Wrap: “Emotionally like, this story is about the legacy of violence among these women and that it really started with Adora. That everything in this story, that’s what we get to know about. So to end it sort of calling back to Adora felt like the original ending for this mystery.”

No matter whose explanation you buy, if any, this will be one of the more polarizing finales of the year — and it could work out great, because controversial endings get people talking. That’s what the “Sharp Objects” team appears to be counting on, especially if some viewers miss the end credits completely.

“A lot of them will stop before seeing it,” Vallée told Vulture. “And then it will become a thing on the Web. And they’ll go, Oh my God, go back if you haven’t seen it.

Read more:

Inside Patricia Clarkson’s brutal ‘Sharp Objects’ performance: ‘It’s dark and nasty and twisted and beautiful’

Review | HBO’s ‘Sharp Objects’ certainly looks like the best show of the summer, but is it?

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