Everybody wants to watch other people having sex. This desire is only increased when the individuals involved are a desperately horny first-grade teacher and a caricatured French waiter, complete with skimpy Fleur-de-Lis boxers. So it is no surprise that the audience of Paula Vogel’s “The Baltimore Waltz” is on the edge of its seat during the scene when Anna (Christine Garver ’08) finally launches into her seventh stage of grief — lust — and begins moaning and gyrating under the tricolor flag.

“Waltz,” directed by Gary Jaffe ’10, follows the adventures of Anna and her brother Carl (Cory Finky ’11) as they travel through Europe towards Vienna, where they hope to find an eccentric doctor to cure Anna’s mysterious fatal illness. Anna’s nymphomania and her brother’s unexplained absences with trench-coated, stuffed-rabbit-waving men are not the only absurdities the siblings confront: A long string of wacky characters (all played by an adaptable Lee Seymour ’09) make up a rich cast of villains, lovers and doctors that Anna and Carl meet during their travels.

What makes the play’s sex scene so successful is not the funny costumes or bilingual screams of pleasure: it is the juxtaposition of Anna and Carl’s experiences. While Anna and her waiter are in the throes of lovemaking, Carl stands on the opposite side of the stage, enjoying an intellectual rant about the paintings he is observing at the Louvre. He ends his monologue as the waiter collapses panting on his sister, saying, “In art, as in life, some things need no translation.”

The play’s main assets are all on full display in this scene. The show transports its audience to an outrageous fantasy world that is equally humorous and disorienting, yet has moments that ring surprisingly true. Carl’s comment is one of many bits of real-life wisdom Vogel subtly sprinkles throughout a show full of absurdity and confusion. Some pieces of dialogue are repeated by different characters in varied contexts throughout the show, lending meaning to an otherwise ordinary phrase. The universal themes of sibling love and barriers in communication provide the audience with something familiar to grasp and give the show a touching realism, as does the poignant twist ending.

The scene also succeeds because of its tight structure, something Vogel emphasizes in the play through the use of Seymour as an interactive narrator moving through short, witty scenes. In the sex scene, the verbal and physical repartee between the three characters is perfectly timed, allowing the actors to bring us both laughter and the revelation of Carl’s final phrase.

But the fast movement of the script means that there are some places where this production lags behind. Often this occurs when minute technical details – a costume change or set shift – distract from the continuous stream of action. More serious is when the execution of monologues and choreography lacks the snap and precision of Vogel’s dialogue. The danger of this whirling intermissionless play is that both the audience and the actors can become exhausted.

Written in 1992, “Waltz” must also confront the challenge of presenting the initial terror of the AIDS crisis to a new generation. “When AIDS first hit there was this question of how you get it. No one knew where it came from,” Jaffe explained in an interview after the show. This uncertainty is reflected in the first full scene, in which a doctor rambles on in frantic unintelligible medical jargon about Anna’s disease, finally positing that she has Acquired Toilet Disease (ATD), probably from sharing a bathroom with her first-graders. While this exchange is funny for anyone with a skeptical view of the medical profession, the exact allusion to AIDS is easily lost on an audience that did not experience the fear and confusion surrounding the early publicity of the virus.

Even with the show’s complicated footwork, there are still plenty of beats to waltz to. Much of the dialogue, soundtrack and costuming (a gruff German lover wears boxers with a Communist hammer and sickle) is fantastic. The actors have believable chemistry and succeed in keeping the audience’s attention. Seymour especially possesses a remarkable ability to bring Vogel’s eccentric characters to life. The Dutch school boy Wilhelm’s story about getting his finger stuck in the dike and the attempts of an old German man to explain the death of Carl’s friend, (“Auto … SHPLATZ!”) are hilarious and captivating.