Blanchett and Fassbender are very good indeed, as both seen-it-all secret agents and middle-aged spouses. Among the film’s high points are the times those two sides of their lives merge. In one, she gently chides him for putting truth serum in the lunch he’s making for the younger quartet of spies,

Not once but twice, as strategic bookends, director Steven Soderbergh’s sleek, droll guessing game “Black Bag” drops us into an intimate gathering at an elegant London townhouse. Around the dining room table are six coworkers,