Greg Sanderson (Robert Carradine) is helping his wife, Jan (Heather Locklear) recover from a nervous breakdown and revive their strained marriage. Their privacy is interrupted by the arrival of Greg's stunning and mysterious sister, Laura (Emma Samms). Jan's paranoia deepens as she suspects that Greg and his sister's relationship is "too close". In her desperation she confides her fears to the landlord (Ned Beatty). But his weird reaction only creates more confusion.