One of the most beloved of all childrenâs book writers tells the story of a seemingly worn-out mare, owned by Mollyâs family, who is carrying a secret: a baby mule! Young Molly thinks the new creature is the most beautiful thing sheâs ever seen. She calls him Brown Sunshine of Sawdust Valley, and as the years go by, Molly discovers that, just like his mother, her mule is full of wonderful surprises.