Who is Gretchen Oyster? The discovery of a series of mysterious handmade postcards distracts Hartley from trouble at home. A poignant novel for fans of Rebecca Stead and Holly Goldberg Sloan. Hartley Staples, near-graduate of middle school, is grappling with the fact that his older brother has run away from home, when he finds a handmade postcard that fascinates him. And soon he spots another. Despite his losing interest in pretty much everything...