The risk of a playwright’s note in a program — that little message penned directly to the audience, no actors or script to get in the way as the writer imparts some context for what the spectators are about to see — is that it can come across as a disclaimer.

In the case of Roberto Aguirre-Sacasa’s note outlining the genesis of his “King of Shadows,” which is making its world premiere in a Working Theater production at Theater for the New City, the seeming disclaimer goes something like this: The play took the shape it took because the grant that paid for it demanded that shape.

That may not be Mr. Aguirre-Sacasa’s intention, but it is the effect, and it goes a long way toward explaining how this passionate dramatist (“Based on a Totally True Story,” “Good Boys and True”) ended up with quite such a pallid, paint-by-numbers piece.

Directed by Working Theater artistic director Connie Grappo, “King of Shadows” is an issue play, the issue being teenage runaways — specifically, gay, lesbian, and transgender runaways in San Francisco, where the play was commissioned. The set, by Wilson Chin, embodies the conflict at the heart of the play, melding upscale domestic contemporary design with gritty, urban streets.

Fifteen-year-old Nihar (Satya Bhabha) has been on those streets for seven months when he meets Jessica (Kat Foster), a wealthy, condescendingly earnest Berkeley graduate student researching her dissertation on homeless youth. Nihar is a Dickensian urchin for the 21st century: tattooed and hip-looking, tough but in an artsily attractive, nonthreatening way. He turns tricks for a living. Also, and this should come as no surprise to those familiar with Mr. Aguirre-Sacasa’s work, his ability to predict the weather may be supernatural, a function of his having lived for years in an underworld called the Kingdom of Shadows.

Eager yet evasive, the puckish Nihar charms Jessica into letting him stay at her house for a couple of nights, a particularly impressive achievement given that Jessica’s 15-year-old sister, Sarah (Sarah Lord), lives with her. But Jessica’s conscience makes her easy prey, and she knows that she and Sarah — orphaned 10 years ago when their parents died in a helicopter crash — have some physical protection waiting at home: Jessica’s boyfriend, Eric (Richard Short), a former New York City police officer transplanted to the Bay Area.

Eric, whose presence in Jessica’s life makes no sense whatsoever, owes his existence to Mr. Aguirre-Sacasa’s need to solve some plot problems with one multitasking character. Like Jessica, Eric is two-dimensional, a type; he’s The Cop, she’s The Guilty Liberal (aka, perhaps, a stand-in for the audience), and they spend a great deal of time trading conflicting, utterly expected sociological arguments on the issue at hand. There’s an ABC Afterschool Special feel to their exchanges, and it isn’t the fault of Ms. Foster or Mr. Short that they can’t find depth or connection where none exists.

Even Nihar is frequently more a type than a human being, lecturing Jessica on runaways for the benefit of her research. Nonetheless, the talented Mr. Bhabha does a remarkable job of breathing life into Nihar, especially in his interactions with Ms. Lord’s Sarah, easily the play’s most compelling character with her intelligence, sarcasm, and comical, spot-on adolescent outrage. She is also the only character who isn’t required to serve as a mouthpiece for a niche demographic.

The waifish Ms. Lord, similarly impressive as a teenager in Daisy Foote’s “Bhutan” at the Cherry Lane Theatre two seasons ago, walks away with the play even as she draws our attention to its core: the story of two lost teenagers from different realms who find a measure of safety and peace in each other. One can’t help wondering what might have been if Mr. Aguirre-Sacasa had concentrated his energies there.

Until September 28 (155 First Ave., between 9th and 10th streets, 212-868-4444).