Life is an adventure for a courageous youngster named Nim, who lives on an exotic island with her marine-biologist father. and a menagerie of animal friends. When Nim's father goes missing, she turns to the only person she knows who can help her: adventurer Alex Rover . But what she doesn't know is that Alex Rover is really Alexandra, a timid recluse. Though faint of heart, Alexandra must find the courage within herself to come to Nim's aid.