As the story opens Gene, the narrator in A Separate Peace, has returned to Devon School, the New England residential boys school he had attended. It's been fifteen years since he graduated and left the school, but he is surprised to find it "looking oddly newer than when I was a student there fifteen years ago."
Specifically, Gene wants to visit two locations that were of pivotal importance to his experience at Devon. "Both were fearful sites, and that was why I wanted to see them." The first of those locations was the First Academy Building, site of the "trial" that Finny was leaving when he fell and rebroke his leg - the event that led to his unexpected death. The second, harder to identify, was "the tree" that "had loomed in my memory as a huge lone spike dominating the riverbank..." and that had been the location of the accident that first broke Finny's leg.