Jamie Dornan and Dakota Johnson in “Fifty Shades Darker.” (Doane Gregory/Universal Pictures) (Doane Gregory/Universal Pictures)

The box-office smash “Fifty Shades of Grey” was a better movie than E.L. James’s “Twilight” fan-fiction deserved. The romance novel about an S&M-loving billionaire who falls for a bookworm was replete with cringe-worthy prose, but the adaptation was saved by a good dose of winking. This is supposed to be ridiculous and fun, the movie assured the audience, and for the most part it was.

With the arrival two years later of “Fifty Shades Darker,” the secret ingredients to the original’s success are clear — especially now that they’re gone. Director Sam Taylor-Johnson and screenwriter Kelly Marcel didn’t return. According to the rumor mill, Taylor-Johnson and James often didn’t see eye to eye.

The author probably didn’t have that problem with “Darker,” since the screenwriter is her husband, Niall Leonard, and director James Foley is no stranger to tawdry, overly serious love affairs. He also directed “Fear,” the Reese Witherspoon-Mark Wahlberg thriller infamous for its climactic roller coaster scene.

The movie picks up not long after the last one ended as Anastasia Steele (Dakota Johnson) ditched her boyfriend Christian Grey (Jamie Dornan), after his love of spanking became more than she could handle. A few weeks on, the recent college grad has landed a job at a publishing house, but she can’t seem to get Christian out of her head — probably because he still sends her roses and shows up at places where he knows she’ll be. She relents the moment Christian asks for a second chance, and this time he promises to keep his kinky toys in his “playroom,” unless she gives him the okay. (Spoiler: She does.)

“Darker” follows a familiar plot — will these two make it work or won’t they? — but with a dash of suspense. For example, someone is watching Ana’s every move, photographing her wherever she goes, making copies of her Social Security card and hacking into her bank account. But enough about Christian, whose bizarre habits send up nary a red flag for Ana. She’s also being hunted by one of her boyfriend’s former lovers (Bella Heathcote), who appears outside Ana’s office looking like a street urchin with crazy in her eyes and a bandage on her wrist. As if two stalkers aren’t enough, Ana also has to deal with an aggressively handsy new boss (Eric Johnson) and the combative older woman (Kim Basinger) who taught Christian everything he knows about flogging.

Johnson has tremendous comic timing, which lightened the mood in the first installment. She’s especially good when her character finds herself in awkward situations, which, for a virginal woman learning the ropes — so to speak — of the S&M world was often. But those opportunities have dried up. This time, she’s expected to emote, and the results aren’t always convincing. Dornan, meanwhile, is basically playing a robot. He’s enigmatic eye candy, with rippling muscles that go a long way toward making up for his nonexistent personality.

Christian does offer, at least, a lot of unintentional comedy, such as when he walks away from a helicopter crash with nothing more than an artfully torn T-shirt or when the billionaire playboy does his morning workout routine on his . . . is that a pommel horse?

Of course, none of that really matters if people simply want to be titillated. In that case, there’s good news. The movie ups the ante with more explicit scenes, including nipple clamps, a stimulating ride in a packed elevator and lipstick body painting (don’t ask).

And then there’s the really good stuff: the spacious kitchen island, the penthouse view and the capable cleaning woman. “Fifty Shades Darker” may be more of a drag than the original, but it still caters to all kinds of fantasies.

“Fifty Shades Darker” (118 minutes, at area theaters) is rated R for strong erotic sexual content, some graphic nudity and language.)