The humorous adventures of an irresistible little rock who finds herself in constantly changing circumstances, Petra is a picture book that celebrates the power of perspective and believing in yourself. 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!.