Using brilliantly ominous visuals and an amazingly unsettling musical score, Panos Cosmatos’ Mandy serves up a simple story that isn’t on the same level of competence as those technical achievements.  Cage and Andrea Riseborough (The Death of Stalin) play Red and Mandy, a soft-spoken bohemian couple who are suddenly captured and tortured by a travelling crew of cultists.  When his girlfriend is kidnapped and used as a pawn for a “special” ritual, Red has no other desire…