The set-up looks ever so calm at the start. In a wisely simple scenic design by Reid Thompson, we see a living room mounted on a low platform center-stage, with the soothing background of a river view. The scene is a Brooklyn apartment with a Christmas tree indicating the holiday season.

We observe Sarah (Miriam Silverman) and boyfriend Sam (Matt Dellapina) sitting on sofa for a quiet evening of togetherness. An interruption comes with knock on the door, and in bursts Nate (Nick Westrate), who lived in the same Manhattan building as Sarah, and we learn that they were long-time friends. We also learn that Nate is feverishly bent on winning her away from Sam.

The above description is totally simplified. In this play, characters speak directly to the audience, past and present are melded, and director Margot Bordelon keeps the author’s mixture flowing smoothly so that we get a perspective on the three characters in their thirties, their personas and the trajectory of their lives within the context of the drama that unfolds.

The playwright has created characters of substance, unlike plays in which we are asked to care about uninteresting people. Sarah is a social worker who at 33 is still unmarried and tells us what that means to a woman. Sam aspires to be a song writer, and Nate’s profession is teaching. All are capable of intellectual conversation about life and its meaning, and we get amusing examples in their dialogue.

What’s more, Ziegler has a gift for writing exquisite passages along the lines of Tennessee Williams’s lyricism. She is also economical in the manner in which she can cover so much territory by her free-flowing integration of moments in the present with the past, abetted by the way in which her characters step out of the action to speak effectively to us.

The three cast members are wonderfully up to the task. Silverman is lovely and believable as Sarah, who seems most likely to marry Sam and gives the impression of a warm, affectionate relationship in the making. Dellapina as Sam conveys a nice guy aura, who at first is bewildered by Nate, but shows his anger as the situation gets out of hand, and he summons the strength to fight for his relationship with Sarah.

The most dynamic performance belongs to Westrate as Nate, who step by step explodes into desperation and reveals a psychotic fixation on Sarah as the answer to is life if only she will marry him. His appearance is jolting to Sam as Nate details a sexual experience with Sarah that seems to have really occurred. Sarah, who clearly has no intention of being with Nate, tries to calm him but also has feelings for him as a friend and human being who shouldn’t be just tossed out of the apartment no matter how disruptive and dangerous he has become.