18. Susannah's secret is revealed at the deb ball.
At the ball, Jeremiah finds Susannah's phone and discovers an email from her doctor about a cancer trial. That's when he realizes her cancer is back. It's a heartbreaking moment. In the book, this scene doesn't take place in front of a crowd of people, but at the Fisher's house. Belly, Jeremiah, and Conrad are all fighting, emotions are high, and it turns physical between Jeremiah and Conrad. The boys have somehow put it together on their own, and that's when Susannah realizes they know. In the show, we actually see the moment Jeremiah finds out.