For Valmont, seducing a virgin is such standard fare it “wouldn’t feel like a conquest.”

At the beginning of Shakespeare’s soaring tragedy, Marc Antony tells Cleopatra: “Now, for the love of Love and her soft hours, let’s not confound the time with conference harsh. There’s not a minute of our lives should stretch without some pleasure now. What sport tonight?”

Let us pause. Two of the world’s most famous lovers ponder empyrean possibilities. Imagine actually saying — or hearing — that in “real life.” Does the heart good.

Now imagine the opposite. Two of the world’s most vile schemers — “virtuosos of deceit” in conference harsh — consider the most lethal means for an epic revenge.

Christopher Hampton’s Les Liaisons Dangereuses takes place in Paris, France, late 1780s. By their estimation, the Marquise de Merteuil and the Vicomte de Valmont have world-class gifts: she’s the supreme seductress; he, the seducer. But when the play begins, the former lovers and now friends — maybe — have been doubly jilted. Her lover, Bastide, ran off with Valmont’s “fat” mistress. “No one has ever done that to me before,” Merteuil complains. “Or to you, I imagine.”

Have the adroit bewitchers lost their knack? Refusing to admit defeat, Valmont sloughs it off. Merteuil, however, orders him to perform “an heroic enterprise”: seduce Bastide’s intended bride, the virtuous Cecile, who has spent most of her life in a convent.

For Valmont, seducing a virgin is such standard fare it “wouldn’t feel like a conquest.” But he’ll do it because Merteuil promised him a sexual favor. And he’ll attempt the impossible: seduce Madame de Tourvel, married, stone-carved faithful, with the moral purity of a Carmelite nun. She will be his masterpiece.

Valmont and Merteuil have the unfettered promiscuity of Greek gods. But unlike the philandering Zeus, or even Antony and Cleopatra, they derive no pleasure from making love. Their pleasure comes from the psychological havoc they create (Valmont says he wants “the pleasure of watching [Tourvel] betray everything that’s most important to her”). And, deeper down, it comes from an unstated battle with each other. Merteuil uses her approval as a control tactic. Valmont’s a needy narcissist — lot of that going around these days — driven to impress her. Everyone else is fodder.

Choderlos de Laclos published his novel, Les Liaisons Dangereuses, in 1782. Christopher Hampton has moved his play forward about five years. The change pulses throughout like a dirge. The French Revolution began in 1789. Its target was aristocrats, of whom the Valmonts and Merteuils rank among the nastiest. As you watch their brutal schemes unfold, you can be sure that Madame Defarge will knit their names in the not too distant future.

New Fortune Theatre’s Richard Baird and Jessica John, as Valmont and Merteuil, underscore their inner dynamics. The audacity of these two — the hypocrisy. How they connive and ruin lives with such straight faces and polished veneers. How they banter with each other, exchanging pleasantries, as oceanic subtexts roil below. It becomes clear, early on, that Valmont and Merteuil are accomplished actors. As are Baird and John.

It’s also clear that something’s changed. Both are slightly off-kilter. They never needed a test before, let alone “heroic” adventures. Here’s where Baird and John shine most of all. How can they, in such a tangled relationship, save face with each other? Each now has an aperture of insecurity, through which the other dives headlong.

Amanda Schaar gives the guileless Torvel such fragile vulnerability, it’s tempting to jump up, race down the aisle, and shout “Valmont’s from hell — run!” Then Schaar shows Torvel might have the strength to resist after all. Even works a kind of secular miracle: she unwillingly causes Valmont to fall in love with her. And falls for him. And falls.

In the inverted world of Les Liaisons, to Valmont and Merteuil, love, tenderness, intimacy are like water to the Wicked Witch. In the novel, Laclos blames “marriages of convenience,” where bride and groom may have little in common, “the most fertile source of those scandalous discords.” Hampton updates the book: a main cause is a morbid fear of intimacy. Even when conspiring, Baird and John make Valmont and Merteuil closed off, almost sealed tombs — except for the expanding aperture that determines their fate when Valmont falls in love.

New Fortune Theatre has taken great risks in staging Liaisons. The technical elements serve it well: a sculpted unit set; flowing period costumes and curly wigs; musical interludes with violas, cellos, and harpsicords; effective lighting that shapes the stage and frames moods.

The risk: it’s a long play loaded with nuance. Audiences accustomed to the pace and Panzer assault of most movies might find it talky and tame. But it’s as violent as previews of coming attractions. The difference: except for a superbly realistic swordfight (choreographed by J. Tyler Jones), the demolitions are internal.

They affect young, duped Danceny (Connor Sullivan, funny but too cartoony), Cecile de Volanges (nicely giddy Gentry Roth), and the staid Madame’s Rosemonde (Dagmar Fields) and Volanges (Terril Miller), whose propriety comes under scrutiny.

They also assault values and conceptions. Characters make whopping statements about men and women, as when Merteuil says, “When it comes to marriage, one man is as good as the next; and even the least accommodating is less trouble than a mother.” As if just saying it makes it true.

Les Liaisons Dangereuses, adapted by Christopher Hampton from the Pierre de Laclos novel

Directed by Richard Baird and Kaitlin O’Neal, cast: Richard Baird, Jessica John, Amanda Schaar, Crystal Brandan, Dagmar Fields, Taylor Henderson, Justin Lang, Neil McDonald, Terril Miller, Gentry Roth, Connor Sullivan, Christopher Torborg; scenic design, Guilio Perrone; costumes, Howard Schmitt; lighting, A.J. Paulin; sound, Mat LeScault-Wood; wigs, Missy Bradstreet; fight coordinator, J. Tyler Jones

New Fortune Theatre, Lyceum Theatre, San Diego Rep, 79 Horton Plaza, downtown; newfortunetheatre.com

Playing through January 28; Wednesday at 7:30 p.m., Thursday through Saturday at 8 p.m. Matinee Saturday and Sunday at 2 p.m.