“War,” written by Branden Jacobs-Jenkins and directed by Lileana Blain-Cruz DRA ’12, is characterized by its tensions: between present and past, brother and sister, family members; across racial divides and language barriers; and between two different shows playing on one stage.

At the beginning, the lights go up on the show’s minimalist stage to reveal two armchairs, two siblings, one comatose mother in one hospital bed and a strange woman by her side who claims in a mixture of heavy German and broken English to be the mother’s sister. Tate and Joanne, the two siblings, have never heard of the woman, who calls herself Elfriede. Further complicating this is the fact that Elfriede is white and German, while Tate, Joanne and their mother Roberta are African-American. What brings them all together is that Roberta has had a stroke.

As Tate and Joanne sit waiting for Roberta to wake up, they are left to confront and reconcile their long-simmering tensions.

Over the course of each act, the two ridicule each other’s decisions and words, from the minor and recent to the lifelong and festering. Gradually, we learn about the family of four that the siblings share even as they divide it. The two decorate the stage with bitter words about loyalty, hypocrisy, Joanne’s decision to drop out of law school and marry a white spouse, and Tate’s career burnout.

As the show delves into the complexities of familial relations, it also experiments with complex narrative forms. From time to time throughout the play, the lighting changes without a moment’s notice, the stage physically rises and the characters — doctors and family alike — drop to all fours and begin to act not as people but apes. Dressed in a ghostly, white hospital gown, Roberta — dazed, amnesiac, lost, confused — wanders among the apes, trying to recover her memory and understand where and who she is. As Roberta stands next to the hospital bed her body occupies, one gets the impression of a purgatory, of an out-of-body experience. A show about family is interlaced with a one-woman act (save, of course, for some apes).

Tonya Perkins, who plays Roberta, delivers a stellar performance, leaving the audience entranced as she weaves in and out of her own consciousness and memory.

Just as chilling are her direct addresses to the audience. She speaks directly to us, asks us who we are, what we are doing here and why we won’t speak back to her.

A common motif of the play is the characters’ breaking of the fourth wall. They often not only interact with the audience, but observe it and make a spectacle of it. The very opening of the play features all of the characters (except Roberta) walking on-stage and slowly breaking into laughter at the audience, as if slowly catching on to some inside joke that only they understand. This image is paralleled at the play’s end, when a group of the characters go to a zoo to look at the ape house and end up looking through a window at the audience itself.

While this adds a surreal element to the play’s many complicated themes and questions, it seemed tangential — if not distracting — to the play’s pathos.

As Tate and Joanne try to grapple with the story (often lost in translation) of this strange German woman and her temperamental son, Tobias, they discover that Elfriede and Roberta share a father.

“I wanted to write a play about black Germans for a very long time,” Jacobs-Jenkins said in an interview published in the playbill. “Specifically something that dealt with the mischlingkinder (children born to white Germans and African-American soldiers during the American occupation of post-WWII Germany).”

Jacobs-Jenkins has constructed a play focused on a unique and unknown component of WWII history, but perhaps the most appealing aspect of “War” is its unique use of the stage. The elevation of the stage to create the rainforest purgatory is enticing. A space in the middle of the stage creates a wall between the characters, a threshold for the apes and a window for the characters to look at the audience. One of the characters exits the stage by walking right off of the downstage steps, joining the audience in the front row. In the physical and the visual, “War” is superb.

However, in its emotional appeal, “War” had its moments of brilliance, but it fell short in its ending. The catharsis it had promised was never fully realized. When the lights dimmed for the final time, I sat at the edge of my seat expecting one more scene. After all, the emotional release had only just begun. But then the audience began to clap, and the players took their finals bows.