I almost stopped reading “Gone Girl” less than halfway through the book.

It’s not that Gillian Flynn’s thriller, about a married woman who disappears and the growing shadow of suspicion that falls on her husband, isn’t well-written or absorbing.

It’s that Flynn, a former Entertainment Weekly writer, painted dual portraits of the husband and wife that were so sharp, so true-to-life, that they were pretty damn uncomfortable.

We’ve all seen this story played out too many times on tabloid TV: Pretty young woman goes missing. Husband seems oddly unmoved. As the police narrow their focus on him as a “person of interest,” he gets a high-profile lawyer. A loud-mouthed TV show host begins what amounts to a public crusade to convict the husband in the court of public opinion.

I almost didn’t have the heart to finish “Gone Girl.” But I kept going and was rewarded with a neat thriller that pulled me in and held me captive until the twisted ending.

Flynn tells the story of Nick and Amy Dunne, young marrieds who lost their jobs in the New York City media (thanks, Internet!) and moved back to his hometown in Missouri.

Nick seems to be a typical boy-man. He’s charming and good-looking but has never grown up. In NYC he ignores his wife and hangs out with buddies, drinking and flirting with women in bars. Back home in Missouri he takes care of his dementia-addled father and runs a bar with his twin sister, Margo (Go for short).

At the beginning of the book, Amy goes missing. At first it looks like she’s been kidnapped, maybe by one of the desperate men put out of work at the town’s only big industry.

But then the police turn their attention and their investigation toward Nick, who begins behaving oddly and outright lying to police.

Interspersed with chapters in the wake of Amy’s disappearance are her diary entries, over a period of several years, that seem to paint a picture of a troubled young woman. Among her troubles: The growing distance between her and her husband and Nick’s increasingly hostile behavior.

I was getting a little tired of Nick’s duplicity and Amy’s insipid second-guessing, but a little less than halfway through the book, Flynn throws readers a nice curve that very nearly turns the second half of the book into a completely new story. No spoilers here. Suffice it to say that, despite – or because of – a conclusion that is quite troubling, Flynn has written a terrific thriller.

Actress Reese Witherspoon is, according to news reports, going to produce a movie version with a screenplay written by Flynn. No word on whether Witherspoon will play Amy but I guess she’d be right for the part.

I’ve already cast Lizzy Caplan as Go. In my head at least.

“Gone Girl” hits so many notes perfectly. The tension between Nick and Amy’s parents after she disappears. The tactics of police investigators (“We want to help you, Nick”) and flashy, high-profile defense attorneys. Best of all is Flynn’s portrait of the Nancy Grace-style TV host, although after creating the character Flynn doesn’t do that much with it.

Flynn has scored a publishing sensation with “Gone Girl” and, if handled the right way, the movie could be a thriller to appeal to grownups.

One caveat: If you’re about to get married or are already married, “Gone Girl” will have you wondering about not only the little quirks of your relationship but the intent of the person on the other side of the bed from you. Flynn’s book is that good and that unsettling.