Nina is an Upper East Side private high school student with all the markers of contemporary urban anomie: Divorced parents (including a mother in rehab following a suicide attempt), a marked lack of supervision, and a friend who encourages her worst instincts. From the school uniform to the bottle of vodka in Dad’s apartment, the signposts of Nina’s troubled adolescence are all on display in Safe, Penny Jackson’s play about a girl whose life is on the precipice; where she’ll land is definitely in question. When Nina meets Phillip, a math teacher turned writer, at the Starbucks where she habitually does her homework, the potential of a dark turn of events emerges.

And turn those events do, though to be frank the result, theatrically speaking, is less than satisfying. At an hour’s running time, the ideas in Safe are too glancingly touched on to offer depth of feeling. While the notion of a teenage girl’s relationship with an adult man being a complicated mix of valuable and skeevy is fascinating, that relationship as presented in Safe merely feels muddled. Things aren’t helped by turns of plot that feel artificial (Phillip’s scenes with Nina’s friend Liz and with Nina’s father being notable examples). With no subplot in sight, Safe relies entirely on the story of Nina and Phillip, and that story is not effective enough to sustain interest.

Director Joan Kane’s production is a mixed bag as well. The perfunctory design elements feature one excellent set piece, a map of Central Park that serves as a sidewalk, and a lot of unmemorable work (though Erica Evans’s costume design does well by the characters). Nick Palladino, as Phillip, struggles unsuccessfully with material that asks him to swerve between being a responsible adult and something less savory (and also less clear). Carolyn Cutillo offers a strong take on Liz, another character asked to take big turns that aren’t always wholly realized in the text. David Lamberton makes a weak impression as Nina’s father; his scenes feel overpowered and false in the tiny theater. Debby Brand, as Nina, saves the day. Her full, engaging performance, deeply committed and fresh, is the lifeblood of the evening. She is terrific.