Describe the events leading to Finny's accident at the tree.

Gene wakes up at sunrise on the beach; he watches dawn break for the first time, while Finny is still sleeping. Gene realizes that he has a math exam in three hours, exactly the amount of time it will take to get back to Devon from the beach; he makes it back in time, but fails the test‹it is, according to him, the first test he has ever failed.

Gene, an academic perfectionist, laments his poor performance on the test to Finny; Finny mocks Gene's ambition to be first in their class, and Gene begins to believe that Finny doesn't want him to do well in school, so that he will come out ahead. Finny excels in athletics, and is definitely the best in the school; Gene knows that he can be the best in the school in academics, but thinks that Finny's high-jinks and his attempts to take up Gene's time are Finny's attempts to make sure that he comes out ahead in the relationship. Gene's jealousy, whether merited or not, begins to take him over; he decides that he cannot trust his "friend," and Finny's statement, that had been so touching the previous evening, of Gene being his best friend, Gene now believes to be false.

Gene soon skips his merrimaking with Finny in favor of studying very hard; he begins to overtake Chet Douglas, Gene's only academic equal, and is proud that he is doing so well in his war against Finny. Finny also begins to study more, but Gene says that Finny is weak academically because he is unable to relate to the kinds of tests they have to take. But Gene finds it hard to keep on hating Finny, because everything is so beautiful and relaxed that summer; he has to make himself feel resentment, which proves to be very hard to do.

When Finny asks Gene to come see one of their club friends jump from their famous tree the evening before their French exam, Gene vehemently objects, and asks Finny if this is his way of trying to sabotage Gene's grades. Finny is not so bleakly competitive as Gene imagined him to be; Finny naively thought that Gene was naturally good at school work, like Finny is at sports, and never needed to study to get good grades. Finny insists that Gene needs to study if he thinks he does; but Gene decides to defy Finny's advice, and, against his better judgment, goes to the jumping tree with Finny.

To start off their meeting of the Super Summer Suicide Society, they decide to do jump off the tree together. Once they are on the tree, Gene "jostles" the limb, and Finny loses his balance and falls; Gene, unshaken, jumps into the river, seemingly without remorse or concern for his friend.