This is no "Free Willy" story. The two sea turtles are a metaphor for the story of two lonely Londoners and what can only be described as their midlife slump. Although it is normally better to read the book first, in this case the film so well honours the book that it works either way.
The book's author, Russell Hoban, is a gifted observer of the tiny details that make up our every-day existence. One perfect example is a scene in which one of the protagonists is crossing the street and looks down and sees a manhole cover with the phrase K257 on it. He steps on it and thinks, "All right, go ahead, play Mozart." When he gets home and looks up the Kochel number, he learns that K257 is the Credo Mass in C. "I believe" is what the manhole cover says to him from that day forward.
It's perfect little associations like these that make this book so brilliant, and so touching. If you have ever felt bitter, or lonely, or lost your faith in humanity, read this book or watch the movie. It works either way and you won't regret it.
