At the closing credits, instead of the regular theme, the credits appear over Marcus singing "The Major-General's Song" (from "The Pirates of Penzance"). Doctor Franklin moans in agony, then you hear the director say, "End credits, very good. Cut." Marcus replies, "What?"
As the credits roll in "Atonement" Jason Carter "Marcus" is singing Gilbert and Sullivan's "I am the very model of a Modern Major General."