Arthur Conan Doyle 
Sherlock Holmes and the Sport of Kings – With Audio Level 1 Oxford Bookworms Library [EPUB ebook] 

A level 1 Oxford Bookworms Library graded reader. This version includes an audio book: listen to the story as you read. Retold for Learners of English by Jennifer Bassett. Horseracing is the sport of kings, perhaps because racehorses are very expensive animals. But when they win, they can make a lot of money for the owners, for the trainers, and for the people who put bets on them. Silver Blaze is a young horse, but already the winner of many races. One night he disappears, and someone kills his trainer. The police want the killer, and the owner wants his horse, but they can’t find them. So what do they do? They write to 221B Baker Street, of course – to ask for the help of the great detective, Sherlock Holmes.