Rosalind and Celia engage in some girl talk, where Rosalind is clearly in an emotional state over Orlando.
Celia marvels that Rosalind could fall in love so quickly, and Rosalind points out that Orlando's dad and her dad were good friends, so (obviously) her love makes complete sense.
This chatter is interrupted by Celia's father, Duke Frederick, who's still storming and dishing out threats of death and destruction. Duke Frederick tells Rosalind that, if she doesn't leave the court immediately, he'll have her killed.
Before she hits the old dusty trail of banishment, though, Rosalind wants to know why she's being sent off.
Duke Frederick lamely claims that Rosalind must leave because she's likely to become a traitor, just like her father. (This is curious, as her father wasn't actually a traitor.)
As Celia pleads for Rosalind, it becomes clear that the Duke is actually jealous of how people look at Rosalind. Duke Frederick tells Celia that she'll look more attractive once her cousin is gone. He emphasizes Rosalind's death sentence once more before going on his merry way.
Understandably, the girls are bummed. This lasts for two minutes before they hatch a plan to run away together to the Forest of Arden where Duke Senior (Celia's uncle/Rosalind's dad) lives with his merry band.
Rosalind points out that it's dangerous for girls to travel alone because "beauty provoketh thieves sooner than gold." Translation: Rosalind doesn't want to be robbed or raped.
Celia suggests they rub "umber" (brown pigment) all over their faces. The idea is that, if they look like dirty peasants who have been working all day out in the sun, maybe they won't attract any unwanted attention.
Rosalind, like all great Shakespearean heroines, has a better idea. She concludes that, because she is the taller of the two, she should dress as a man. Rosalind decides to be called "Ganymede."
Celia won't disguise her gender but she'll pretend to be "Aliena," which means "the estranged one" in Latin. (Think "alien" and you have a clever reference to Celia's state of self-banishment.)
We interrupt this program for a brain snack. In classical mythology, "Ganymede" is the name of the young hottie who was kidnapped by Jove, who made him his official cupbearer. In Elizabethan England, the name "Ganymede" was a term applied to the kind of young man who had a sugar daddy. In other words, the name "Ganymede" is synonymous with (male) same-sex desire, which is something you'll want to keep in mind as you read.
The girls decide to take along Touchstone, the court fool, because he's so fun to be around and will keep everyone from being bored in the woods.
Celia declares that they go into the forest of Arden " to liberty, and not to banishment."