Sophie is different, and she likes it that way. She wears overalls, eats black licorice, and likes to dig in her backyard. Most important of all, Sophie likes secrets --- any secret at all. When her neighbor, Dot, enlists her help to take care of a community garden, Sophie is surprised to discover an unusual secret: souvenirs are appearing there, and she doesn't know why. Who's leaving them? And why? All she knows is that she has to find out.