Wholesale Mysterious Edge of the Heroic World by E.L. Konigsburg

[Atheneum Books for Young Readers] Discoveries Amedeo Kaplan dreams of discovering something -- some treasure no one realizes is there until he finds it. And he would like to discover a true friend to share this with. Improbably, he finds the friend in aloof, edgy William Wilcox. And even more improbably, he finds his treasure among the memorabilia in the house of his eccentric neighbor, Mrs. Zender. But Amedeo and William find more than treasure -- they find a story that links a sketch, a young boy's life, an old man's reminiscence, and a painful secret dating back to the outrages of Nazi Germany. And they discover unexpected truths about art, friendship, history, heroism, and the mysteries of the human heart.