The entire epic history of the Earth and the Moon is recounted through the observations of one special moon rock named Bok. Geologists say that rocks remember, and Bok certainly does. It recounts how its life began on Earth, until a collision with an asteroid catapults it into orbit during the creation of the Moon. From the Moon's surface, Bok watches the developing planet change from afar--until a strange creature scoops him up and brings him back to Earth.