Turtle in a tree

Summary/Review: "A greyhound swears there's a turtle in the tree. A bulldog says it's a squirrel. After all, a turtle in a tree? Who's ever heard of such a thing? But their argument leads to a most surprising discovery . . . that maybe neither one of them is all the way wrong, or all the way right, and friendship is all about listening to someone else's perspective." --Amazon.com.