It seems silly to judge an entire play based on one face slap. But when Ann (René Augesen) strikes her insensitive husband, Peter (Anthony Fusco), in a pivotal scene in Edward Albee's marital melodrama, its tepidness speaks volumes about the lack of edginess in A.C.T.'s latest production. What should be a slap of passion — he has just dismissed his wife's needs after she reveals her deepest desires — instead comes across as a playful admonishment. While the cast and director do a fine job of setting up a world where the threat of violence hums underneath a refined upper-middle-class surface, the violence has a staged, distant quality when it finally boils over. Albee still knows how to turn a phrase and use few words to get right at what most terrifies comfortably affluent couples. But the production doesn't dig deep enough beneath the words to truly shake us and disturb us as it should.