You’ve been there a hundred times before. You are racing into the subway entrance. A homeless panhandler aggressively demands change. You briskly speed up, certain that the money would only go to drugs and that your taxes are supporting a flood of social services this aggressor should use. In Scorpions, Mark Scharf’s new play for the Baltimore Playwrights Festival, the scenario has suddenly changed. William, a prim office worker, discovers that Mattie, the homeless beggar staking out a Washington subway stop, is more than meets the eye. Intrigued by the witty, Dickens-citing panhandler, William puts Mattie up at his apartment, brings her to the company happy hour, and starts an affair that may be more than Platonic. A hateful coworker, Derek specializes in humiliating William through racial slurs on William’s Asian background and destroys his colleague’s quirky affair through an attempted seduction of Mattie. Scharf’s dialogue crackles through this play’s combination of comedy and melodrama. The sharp witty passages soften the somber action and outcome of the play. The dramatic scenes, notably the attempted seduction of Mattie, bristle with brittle, humiliating conflict. The play occasionally lags, as in the dangling monologues and in the more pedantic musings on ethnicity. But it successfully avoids the stereotypes associated with this genre of theater and keeps both he offbeat comedy and the emotional conflict of the piece on track. Despite a cumbersome set, which seems to have more furniture than the Ethan Allen showroom, director Miriam Bazensky briskly moves the action toward its bitter conclusion. Robin Rouse gives the standout performance as Mattie. Her sharp barbs and bravura gestures intensify the comic aura of the production; her breakdown after the humiliating encounter with Derek constitutes the performance’s emotional apex. Playing at the Fells Point Corner Theater, Scorpions offers a grim but entertaining glimpse of the relationship beyond dysfunctional.