Tallulah doesn't look like the other young mermaids living in the ocean. Her tail is a dull gray. And when all the other mermaids go on a quest to find the special gemstones that make their tails sparkle with color, Tallulah doesn't find her gemstone at all. When Turtle suggests that Tallulah searches the Great Lakes she is eager to give it a try, even though the other sea creatures believe mermaids don't belong in lakes. Tallulah explores the Great Lakes from north to south and east to west, until she finds a beautiful Petoskey stone and she realizes that she is finally exactly where she belongs.