Matt Williams’s Fear, presented by Cherry Lane Theatre and running at the Lucille Lortel Theatre, begins with Phil (Enrico Colantoni) dragging 15-year-old Jamie (Alexander Garfin) on stage in a stranglehold. “Why were you at the lake?” Phil demands, in the abandoned tool shed where he takes his prisoner (scenic design by Andrew Boyce). At its best, Fear, soundly directed by Tea Alagić, is propelled by mystery and frayed nerves, with the potential for violence looming. The confrontation is not just between Phil and Jamie, but soon Ethan (Obi Abili) stumbles upon the unusual scene—with Jamie now tied to a chair—and the story of a missing girl in a suburban New Jersey neighborhood becomes about class and cultural conflict.