Sherlock Holmes has retired. But when MacDonald asks him to take on another case, he says yes. There have been some mysterious murders, and there are no visible causes for the deaths. At the same time Holmes gets this case, Graf Udo Von Felseck gives him another case: find a young and missing prince to prevent war between Germany and England. But Von Felseck is not as honest as he seems.
In a remote area of Dartmoor, The Silver Blaze, England's most famous and valuable racehorse, goes missing, the dead body of the horse's trainer is found, and sheep are savaged. The Police seem bewildered, but then they charge Fitzroy Stephen, a famous figure in the racing world, with the murder. Holmes is called in to trace the missing horse and finds he has to separate fact from fiction.