Liar & Spy by Rebecca Stead: Summary and reviews
https://www.bookbrowse.com/reviews/index.cfm/book_number/2763/liar-spy
Liar & Spy is an inspired, often-funny story about destiny, goofy brilliance, and courage. Like Stead's Newbery Medal-winning When You Reach Me, it will keep readers guessing until the end When seventh grader Georges (the S is silent) moves into a Brooklyn apartment building, he meets Safer, a twelve-year-old coffee-drinking loner and self-appointed spy.