Hostility crackles through the first act of "The Gingham Dog," currently at the Back Alley Theater. An interracial marriage is in its death throes, and it's a bitter, noisy death. It's unusual for a play to open with such a full head of steam.

Unfortunately, after intermission the steam escapes rather than builds.

In the end, Lanford Wilson's play is nothing but an ending. He offers only bare hints of the beginning and middle of his story. The question is not "Can This Marriage Be Saved?" It's "How Did It Ever Begin in the First Place, and When Will It Finally Drop Dead?"

Nevertheless, "The Gingham Dog" does have its theatrically vigorous moments. And the political issues raised in the play in 1968 have dated less than they should have.

The crumbling of the integration ethic that's apparent in the dissolving black-white marriage of Wilson's play is also apparent today in the public furor and private musings aroused by the Bakke and Weber cases. In surprisingly potent fashion, Wilson analyzes the clash of rising black expectations and rising white backlash through a portrait of one marriage.

The white husband, Vincent, fled a small Southern town in order to be a New York liberal. But now he finds himself working for an architect who designs slum tenements. And he finds Gloria, his wife of three years, increasingly critical of his job, his bigoted relatives, and what she sees as her own retreat into domesticity and naive colorblindness.

The Back Alley production is strongest during the fierce arguments of the first act. Mark Selinger is a nervous wreck as Vincent, and Linda Shockley's Gloria alternates well between sardonic cynicism and raising rage. Akim Nowak and Melissa Craig make striking appearances in problematic supporting roles.

As the play becomes more enervated in the second and final act, so does the pace of Fredric Lee's direction.