The valley of fear by Doyle, Arthur Conan

When Sherlock Holmes receives a bungled tip-off from one of the agents of his nemesis, Professor Moriarty, the great detective hopes to avoid a murderous crime and bring the would-be assassin to justice. But on being informed soon afterwards that one John Douglas of Birlstone Manor has been found with his head blown apart by a shotgun, he realizes that he is too late. And so begins an enthralling tale of revenge, vigilantism and secret societies, one that transports the reader from the English countryside to the violent world of the American frontier of the 1860s.