Sir Arthur Conan Doyle, creator of Sherlock Holmes, has his own mystery to solve when he answers a call from George Edalji, who claims to have been falsely convicted of mutilating animals and imprisoned. Edalji had been accused in a series of anonymous letters and Conan Doyle finds that the police seem to have reinterpreted evidence to fit the accused's movement. His spirited defense of Edalji in a newspaper article leads to friction with the powers that be, particularly in the police.