The next morning, Evie wakes up early and puts on one of her mom's new dresses. She twists her hair up and does her make-up—even putting on the dark red lipstick that her mother wears.
Later, at the courthouse, Evie shows up with Mr. Markel. Her parents don't have time to talk to her before she goes into the courthouse, and they don't know what she's about to do. Maybe that's for the best.
She walks up to the front of the courtroom and sits down, trying to look as grown-up and beautiful as possible—and when she testifies, she tells him that she was the one who was having an affair with Peter Coleridge.
Evie says that Wally saw her that night kissing Peter—she was wearing her mom's best dress. She also says that she regularly went to meet with him at the house he'd broken into.
She also tells them that she was in love with Peter Coleridge, which is the one solidly true thing that she's said on the stand.
As she's sitting there, she can see Peter's father in the back. He's staring at her.
Evie tells everyone that on the day her parents went boating, Wally forced himself onto her—and that maybe he blamed her for getting fired and held a grudge against her family.
Then Evie is done. As she walks down the aisle to leave, she passes by Peter's father, who looks at her with so much contempt that she starts to cry.