Narrated by Ryan Reynolds, it tells the story of Luna, a killer whale (orca) living in Nootka Sound, Canada, who was separated from his pod at a young age.

The reworked version was rewritten to tell the story from a third-person perspective and focuses less on the directors' personal involvement in Luna's life.

[2] Andy Webster of The New York Times suggested that "A documentary ideal for schoolrooms, family viewing, and discussion",[3] while Todd McCarthy of The Hollywood Reporter, called the film "Serious-minded, thought-provoking animal documentary [that] will have a lengthy life, mostly in ancillary markets".

Brian Miller of The Village Voice said that "[w]hile they fluff up the conflict between the "no touching" feds and Luna-besotted locals, all parties are simply too polite, decent, and Canadian for any real drama".

According to him, "[the] [d]ocu[mentary] dotes on its adorable, highly photogenic star, but nonstop voiceover commentary and exclamations of wonderment tend to lessen rather than enhance its impact".