In the novel "A Separate Peace"...?

Just before Leper's telegram arrives at the end of Chapter 9, Gene describes the Winter Carnival as a liberating experience, a momentary escape that created an "illusory, special and separate peace." Based on the descriptions of the Winter Carnival and the cirstances that the boys face in this novel, what does it mean to create a separate peace and why is a separate peace so valuable to them all? How does Leper’s telegram contrast with that “separate peace”?