Piper, a rebellious young dolphin, breaks the rules of her Pod and is exiled to the open sea. Lonely and afraid, she nevertheless comes to the rescue of a much larger, older creature under attack by orcas. As he recuperates, they travel together to the western shores and back. He explains mysteries and truths of the vast seas and becomes a friend and mentor, and she gains a reverence for the sea and learns much. Some of her new knowledge is alarming—an unexpected danger may soon threaten her loved ones at home. Should she risk returning to her clan in hopes of forewarning them? If she does, will they heed her desperate pleas or remain entrenched in their own ignorance?