It all starts with the death of a proton. When budding astronomer Will Tuppence learns a proton was observed in the act of disintegration, his stable world tilts. If he can’t even trust in the permanence of atoms, how is he supposed to manage the more tangible but no less overwhelming obstacles in his life? Like his confusing relationship with best friend Mi-Su, which seems to be taking a romantic turn, or his ongoing battles with his kindergarten sister Tabby (a memorable creation who could be the love child of Beverly Cleary’s Ramona and Judy Blume’s Fudge). There are also the small matters of defending his local chess title and planning the perfect date with Mi-Su. A tragic accident helps Will understand that life and first kisses can’t always be scheduled, and sometimes it’s better that way. Another solid, feel-good offering from Spinelli that takes big themes about love and the meaning of life and cuts them down to kid-size with finely tuned characterizations and humorous dialogue. Stargirl would approve. (Fiction. 11-14)