Story rhythm arises when values within a section of narrative alternate in charge. This can happen within a single scene, between scenes within an act, and between correlated scenes within different acts. McKee reminds us, for example, that the two most powerful scenes in a story are the last two act climaxes. Seen as a unit, they orchestrate a crucial rhythm, which can only arise if the value of the one scene differs from the other.
If the Hero achieves an aspect of his goal at the end of the second act, the climax of the next act must be negative—she must fail to achieve her goal in some important way. In the words of McKee, “You cannot set up an up-ending with an up-ending… (or)…a down-ending with a down-ending.” Things can’t be great, then get even better, or bad and get even worse. That’s slack storytelling devoid of tension. If you want an up-ending, set up the previous act’s climax to yield a negative charge, and vice versa.
Irony as Climax
If a story climaxes in irony, however, the result is an ending that contains both positive and negative charges, although one value tends to gain prominence over the other. McKee offers the example of Othello as an illustration of this. In the play, the Moor achieves his goal/desire to have a wife who loves him and has never betrayed him with another man (positive charge). But he only discovers this after he has murdered her (negative charge). The overall effect is one of negative irony. Positive irony is achieved when the positive charge prevails. In the film of the same name, Mrs. Soffel (Diane Keaton) goes to prison for life (negative irony). But she does so having achieved her life’s desire of having achieved a transcendent romantic experience (positive irony).
Story rhythm is established when important scenes alternate in value. If a scene ends with a negative charge, its correlating scene must end in a positive one, and vice versa. This, of course, need not be on a scene-by-scene basis. Correlation can exist between scenes that are separated by many others. Typically, the penultimate and final climax scenes are correlated, as are many others.