Christopher Hampton's "Les Liaisons Dangereuses" smolders with passion and desire. But the emotional temperature in Huntington Theatre Company's production never rises above lukewarm.

The problem is with Michael T. Weiss and Tasha Lawrence, who play ex-lovers in 18th century France. They value betrayal and cruelty, and entertain each other by humiliating others. Both Weiss and Lawrence have a white-knuckle grip on their characters' coldly manipulative qualities but leave no room for vulnerability, which destroys the play's essential plot twist.

When La Marquise de Merteuil (Lawrence) asks Le Vicomte de Valmont (Weiss) to seduce her ex-lover's young bride-to-be as revenge for dumping her, Valmont agrees because it fits into his own plans to seduce the highly moral Madame de Tourvel (Yvonne Woods). What follows is an elaborate series of seductions, fueled by Hampton's clever double-entendres and witty wordplay.

But, under the direction of Daniel Goldstein, the seductions - of the virgin Cecile (Louisa Krause), her suitor Le Chevalier Danceny (Jeff Barry) and Tourvel - have all the sensuality of a medical textbook. There is nothing romantic, alluring or tempting about Weiss' approach to Valmont's sullying of Cecile, which makes it ridiculous when she says she invited him back the following night. There is zero chemistry between Woods and Weiss, and Krause's Cecile looks more like a scared bunny than a woman struggling with her desire to jump into bed with Valmont.

Most importantly, both Weiss and Lawrence miss the moment when their characters reveal the chink in their emotional armor. Merteuil explains that as a woman with few options in the repressive French society, she had to become a virtuoso of deceit, but she never makes clear the toll it's taken on her. Valmont admits several times that Madame de Tourvel has an unexpected hold on him, but as Weiss never connects with her, the words are empty.

The set and costumes also work against each other. James Noone has designed a sumptuous multitiered set that creates a lovely sense of flow from scene to scene. Mark Stanley's flickering candelabras are utterly exquisite, and his shadows and light become another character, complicit in the deceptions.

But Erin Chainani's costumes tend toward gaudy when they should be gorgeous. A red leather jacket and later a gypsy get-up are completely over the top, and the arrival of a character wearing a Chanel suit circa 1780 suggests Chainani's channeling Cocoa Puffs, not Coco Chanel.

The only thing dangerous about these liaisons is the possibility of death by mediocrity.

"Les Liaisons Dangereuses," presented by the Huntington Theatre Company at the Boston University Theatre, through Feb. 5.