"Oh, let's do it!" say Kitty and Katy and Mom when a thousand-piece jigsaw puzzle mysteriously arrives in the mail. "I have time on my hands," agrees Dad. Starting in winter with the edges, by autumn they're almost done, only to discover that one piece is missing. Mom is sure that it must have accidentally gone out with the trash, so the Kellys pile into the car to comb through the local dump ("shouldn't take long"). There they uncover forgotten letters, train tickets, discarded newspapers, and old photos yellow with age, but finding the missing piece is starting to seem like wishful thinking