There's nothing Molly wants more than a horse of her very own. She doesn't care if it's a filly or a colt. Just as long as it's young and strong and can gallop faster than mean Freddy Westover's old mare Della.
Then Molly's dream comes true: She's getting her own horse! But the mare she's getting isn't quite what Molly wanted. Lady Sue's so old and worm out, she's probably slower than Della!
But Lady Sue has a surprise for Molly that's better than anything-- a baby mule! Molly plans to turn Brown Sunshine into a hard worker and a good friend. But Brown Sunshine may have a few surprises in store for her.