Playing Janet Leigh, the woman famously knifed to death in the “Psycho” shower scene, Johansson brings a sweetness to the late actor, who tolerated the violent mood swings of her director. Janet is sometimes appalled by the behavior of Hitchcock (Anthony Hopkins) but treats him with a kindness and understanding that her co-stars do not share. At one point Hitchcock’s wife, Alma (Helen Mirren), thanks Janet for being such a professional; the moment speaks volumes about the two women, both victims and beneficiaries of Hitchcock’s genius.