Petra is a little rock who believes she is a mighty mountain . . . until a dog fetches her for its owner, and she is tossed into a bird's nest. A mountain? No, Petra is now an egg! An egg of the world in a world of possibility. Until she's flung into a pond, and becomes an amazing island . . . and, eventually, a little girl's pet rock. What will she be tomorrow? Who knows? But she's a rock, and this is how she rolls!