Ben Affleck, Patrick Fugit, David Clennon, Lisa Barnes and Kim Dickens in a scene from “Gone Girl.” (20th Century Fox, Merrick Morton/AP)

(Warning: This post contains LOTS of spoilers about the movie.)

“The hallmark of a sociopath is a lack of empathy,” cable news host Ellen Abbott explains breathlessly to her millions of viewers in “Gone Girl,” the film adaptation of Gillian Flynn’s twisted mystery novel that ruled the box office last weekend. Underneath Ellen’s face on screen, a headline reads “Nick Dunne: Wife Killer?”

That question mark is very telling, because Ellen (Missi Pyle) — designed as a Nancy Grace-type character within the film’s world — has no idea if Nick did anything wrong. All she knows is that Amy Dunne disappeared from her home in Missouri on her fifth wedding anniversary, and her emotionless husband looks very suspicious. So why not drum up some ratings and declare he might as well be guilty?

The film, directed by David Fincher with a screenplay written by Flynn, has great fun skewering the Ellen Abbott model of cable news and the tabloid media world in general, which can zero in on a suspect without real proof. And it’s not like this is too far fetched. Just last week, the New York Post settled a defamation lawsuit after it published a photo of two innocent men after the Boston Marathon bombing, implying police were searching for them.

Obviously, the Ellen character in “Gone Girl” is based on Nancy Grace, the HLN cable anchor who has made a fortune discussing every detail of high-profile crime stories on TV. She also sees a major bump in viewers when she rallies behind a specific trial. One of her most famous examples: Casey Anthony, whom she dubbed “Tot Mom.” Grace was furious when Anthony was found not guilty of killing her toddler daughter, Caylee.

“In the end, Tot Mom’s lies seemed to have worked,” Grace ranted to her viewers after the verdict, later adding, “The devil is dancing tonight!”

“Gone Girl” attempts to parody that type of breathless news, even if it’s not so far from the truth. Ellen endlessly exploits Amy’s disappearance, dissecting every minor detail and happily drawing her own conclusions. She hosts Noelle Hawthorne (Casey Wilson), the woman who claims Amy was her best friend, even though there’s no way to verify any of her information.

Abbott also feels free to say anything for shock value, such as speculating that Nick and his twin sister, Margo, seem to be very close for siblings. Very, very close — get it?

“Twincest,” whispers a man in the airport who’s watching, as Nick slumps down in his seat and covers his face with a baseball hat.

The movie explores just how dangerous the media bandwagon can be in a case with no answers but one very enticing suspect, as Nick’s house is swarmed by paparazzi and news cameras constantly.

The most telling moment comes at the end (again, spoilers), when it’s revealed that no, Nick did not kill Amy — she went on the run after elaborately framing him for her murder. In fact, it’s Amy who is the murderer — she winds up killing her ex-boyfriend, Desi (Neil Patrick Harris), whom she ran to when all of her money was stolen. She frames him for kidnapping and raping her through an elaborate and brutal murder scene, and the police have no choice but to buy her story.

So what happens the next time we see Ellen on TV? The movie deftly shows us how quickly the media can pivot to a new target without a second thought: She’s prattling on about how Desi was obviously an obsessed ex all along. She doesn’t even mention Nick.

Nick and Ellen meet once at the end of the movie when she arrives to do a final interview about Nick and Amy’s “happy” reunion. When an angry Nick reminds her that she turned the world against him and even told people that he was possibly sleeping with his twin sister, Ellen shrugs it off.

“I never said the ‘i’ word,” Ellen says defensively, adding that she only said the two were “extremely close.” Then she brightly switches gears and hands Nick a present.

Yep, no harm done — just ruined someone’s reputation forever. And it would be a lot scarier if it wasn’t so close to real life.

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