“Dangerous Liasons” by Christopher Hampton offers a pair of characters with velvety voices, smooth manners and a total lack of conscience, who prey on others in their circle of acquaintances in Paris circa 1920s.

Deliciously nasty roles for skilled actors Haley Johnson and Nils Swanson, who portray Madame de Merteuil; and the Vicomte de Valmont in the opening production by Spark Theatre. It takes place in a small upstairs room with 30 chairs at one edge and a rug. But theater it surely is.

Costumed household servants move a few prop pieces to create different scenes: at Merteuil’s town house and at the country home of the Vicomte’s elderly Aunt, where he stages several conquests in this melodramatic piece. (Think soap opera with fancy words). “Love is a medicine-used as a lubricant in nature...”

The audience can’t help but feel involved in the action, and perhaps wonder if they shouldn’t intervene? It adds to the success of this compelling piece, directed by Michael Emmitt, who is bravely offering a different and appealing way to see and hear a story.

Kelly Reeves, the unfortunate Madame de Tourvel— one of the Vicomte’s targets because she is pious and conservative, as well as attractive — gives a solid performance, at times, almost in the laps of the front row.

Another victim is the young, virginal Cecile (Mollie Adams-Denner), suggested by Merteuil because she has attracted the attention of the madame’s young lover Danceny (Brian Kusic).

One almost needs a score card. A steady thread is the underlying tie between Madame and the Vicomte, which neither really acknowledges.

Liasons can certainly be dangerous. And in this case, entertaining.