The Happy Hollisters at Pony Hill Farm

This story introduces a mystery on almost the first page, when the Hollisters attend an auction sale at Stone Farm near Shoreham. When Mr. Stone died he had only one relative, his grandson, Graham. Graham had been informed that he was to have the one thing of value on the farm, known only as "mystery boy." Unfortunately, no one knew who or what "mystery boy" was. The Hollisters, therefore, were quite surprised to find that the hobby-horse they purchased at the sale held the key to the identity of this strange bequest.