The Chicago premiere Disappeared , by Phyllis Nagy, will not vanish from the Steppenwolf Studio Feb. 28 as originally scheduled. The production has been extended through March 14, with the possibility of another extension through the end of March.

The original New York show, written by London-famed Nagy, opened at Chicago's Steppenwolf Theatre Feb. 3. This mounting marked the first collaboration between Roadworks Productions and the Steppenwolf Theatre Company.

Disappeared is the story of Sarah Casey, a young travel agent who suddenly vanishes from a dingy Manhattan bar. Hell's Kitchen, O'Malley's Saloon and the NYPD are examined in the story, as is Elston Rupp, a thrift store clerk who may have kidnapped Casey, or, perhaps, escaped along with her.

Though U.S. born, Nagy found her fame overseas. Her most recent play, Neverland , opened at the Royal Court Theatre and is scheduled to transfer to a West End theatre.

The Roadworks staging stars Debbie Bisno, Stephanie Childers, Marilyn Dodds Frank, Derek Hasenstab, Danny McCarthy, Larry Neumann Jr., Si Osborne and Nathan Rankin. Abagail Deser directs. Previous Roadworks productions include the Chicago premieres of SubUrbia , Ecstasy and Dealer's Choice. For information, call (312) 335-1650.

-- By Robert Simonson and Becki Heller