What is the falling action of Lysistrata?

Falling action refers to the part of a plot that takes place after the climax has been reached. The climax of Lysistrata happens when the Spartan herald approaches the Acropolis in a state of advanced tumescence pleading for a treaty to conclude the war between Sparta and Athens. Delegations from both sides arrive at the Acropolis. Like the herald, they are all highly aroused due to the women's extended sex strike, and they are desperate to thrash out an agreement. This point in the play is the climax because the action has changed the protagonist's fate, the protagonist in question being Lysistrata, of course.
The falling action consists of Lysistrata brokering a peace treaty between the warring factions. She makes the delegates see sense and realize that they share a common heritage and owe a debt to one another. The reconciliation that marks the falling action of the play also extends to the respective choruses: the Chorus of Old Men and the Chorus of Old Women.