Mariane Timeline and Summary

Mariane arrives at Harpagon's house and realizes that Harpagon (her prospective fiancé) is the father of the man she really loves, Cléante.
Mariane agrees with Cléante and Frosine to hatch a plan that will get Harpagon to reject her.
After the plan is made, Mariane leaves to spend the afternoon with Élise.
When Mariane returns to the house, she hears the servant Valère tell a story about how he was separated from his family in a shipwreck when he was young. She recognizes the story (because it happened to her, too) and shouts out that she must be Valère's sister.
On top of all that, it turns out that the kind old Anselme is actually their long lost father.
Anselme vows to spend as much money as it takes to make sure that Mariane gets to marry Cléante. They leave the stage feeling good about the upcoming wedding.