If E. L. James accomplished nothing more with her dunderhead, abysmally written internationally best-selling Fifty Shades of Grey erotic book trilogy, she at least brought to airport and mall bookstores a conversation of tops, bottoms, whips, spanking, handcuffs, chains, ropes, slings, and tit clamps and butt plugs.

A movie version being inevitable, this Valentine’s Day gift to the world of schlock cinema, scripted by Kelly Marcel (Saving Mr. Banks) and directed by Sam Taylor-Johnson (Nowhere Boy), tries valiantly to elevate the Twilight fan fiction-inspired source material to a level of melodrama worthy of ‘60s stuff like A Summer Place or Strangers When We Meet. It sometimes succeeds but just as often, it sloshes around in a bubble bath of high camp a la 9 ½ Weeks. Filmed like a glossy, fetishistic as a perfume commercial, the movie doesn’t have the courage of its lurid convictions and its timid sex scenes (15 minutes of them) are punctuated by breathy anthems by pop divas like Beyoncé. So, gird your loins for theaters filled with nervous giggling women, who will probably hate it because it doesn’t star the people they imagined in the leading roles.

The film’s plot is as simple as its sexual politics are muddled. Virginal college senior and wide-eyed naïf Anastasia Steele (Dakota Johnson) gets swept off her feet by impossibly rich, emotionally closeted CEO Christian Grey (Jamie Dornan) — a secret sadistic dom equipped with a playroom full of expensive S&M paraphernalia. He wants her to be his one and only exclusive sub. He demands total control in every aspect of his life, especially sexual. She, of course, sees the pain in his eyes, falls in love with him and wants to rescue him from herself. Complications, conversations about non-disclosure contracts, awkward dinners with stick figure parents, and mild kink ensue.

The thing really isn’t about sex, of course, it’s about power. It floats in a female wish-fulfillment world of ridiculously handsome, chiseled dudes so engorged with desire that they whisk away average-looking virgins on their self-piloted private jets to their lavish penthouses featuring walk-in closets the size of Texas, drawers lined with an endless assortment of grey silk ties and, just for fun, a secret torture chamber so well-appointed, neat, and hermetically-sealed that it might pass muster on HGTV. Start asking some simple questions like, “If Christian Grey is so obsessively secretive, then who cleans, straightens, and polishes his playroom after he and his playmates have had their fun?” and the whole thing collapses like a deflated football. Aside from some funny (intentionally funny, that is) dialogue from Ms. Marcel and satirical touches and knowing winks from Ms. Taylor-Johnson, the movie has almost as many lines of howler dialogue as Jupiter Ascending.

Dakota Johnson makes the movie worth seeing – even when she’s required to put a spin on lines like, “What’s a butt plug?” The granddaughter of Tippi Hedren and daughter of Melanie Griffith and Don Johnson, Johnson gives her loopy, inconsistently-motivated character charm, sardonic humor, lively wit, and, yep, steel. Ferociously brave and beautiful in her frequent nudity, it’s she who’s stuck with most of the heavy lifting along with the heavy breathing. By contrast, Jamie Dornan, on target as an emotionless serial killer on the gripping Brit TV series The Fall, seems glum, stiff, and dead-eyed. Sure, he’s saddled with an impossible role to play, but he doesn’t bring much to the party except his torso and his S&M toys. At least the makers have the good sense to let him say, “I’m fifty shades of fucked-up” with his back turned to the viewer. Otherwise, we might see him laughing as hard as the rest of us are. In the end, Fifty Shades of Grey isn’t so much terrible as it is timid and tame. ** ½