Hardy Boys 15: the Sinister Signpost

In "The Sinister Signpost," the fifteenth book in the classic Hardy Boys series, brothers Frank and Joe Hardy dive into a dangerous case for their detective father. They investigate a series of mysterious race car accidents where drivers report seeing a "DANGER" signpost that then vanishes. The plot thickens with an attempted theft of an experimental motor and the kidnapping of a famous racehorse. This book, originally published in 1936, offers a fast-paced, action-packed mystery that will appeal to young readers aged 8-11 who enjoy detective stories and adventure. Parents should be aware that, as an unrevised original edition, it contains language and character portrayals that reflect the social attitudes of its time, specifically regarding the villain's description as a "swarthy" foreigner.