Forgive Me, Leonard Peacock

In addition to the P-38, there are four gifts, one for each of my friends. I want to say good-bye to them properly. I want to give them each something to remember me by. To let them know I really cared about them and I'm sorry I couldn't be more than I was--that I couldn't stick around--and that what's going to happen today isn't their fault.
Today is Leonard Peacock's birthday. It is also the day he hides a gun in his backpack. Because today is the day he will kill his former best friend, and then himself, with his grandfather's P-38 pistol.
But first he must say good-bye to the four people who matter most to him: his Humphrey Bogart--obsessed next-door neighbor, Walt; his classmate Baback, a violin virtuoso; Lauren, the Christian homeschooler he has a crush on; and Herr Silverman, who teaches the high school's class on the Holocaust. Speaking to each in turn, Leonard slowly reveals his secrets as the hours tick by and the moment of truth approaches.
In this riveting book, acclaimed author Matthew Quick unflinchingly examines the impossible choices that must be made--and the light in us all that never goes out.