"Proof" has a series of dramatic surprises, including a first-act curtain that audiences greet with an audible sigh.

In "Getting Away With Murder," I started from what I wanted for a first-act curtain.

A.S.: I guessed that you had started with your first-act curtain.

(Ms. Zambello, apparently in exasperation, has an enemy soldier come out and shoot him dead at the first-act curtain.)

The one to ring down a first-act curtain?

With all that tumult, how is it that the first-act curtain falls flat?

That must have made a fine first-act curtain, but the story doesn't have anywhere interesting to go once Kate, appropriately humiliated, slinks away.

In a hapless first-act curtain, the actor and director conjoin in ineffectuality.

This, lamentably, was the story of Christina's life: though her first-act curtain was arguably the most dramatic of any in 17th-century Europe, she had no second act.