On 17 August, 1860, wealthy widow Mary Emsley was found dead at home, killed by a blow to the head. What followed was a murder case that gripped the nation. There was an abundance of suspects, from disgruntled step-children and a spurned admirer to a trusted employee, former police officer and spy. A sensational trial culminated with a public execution, but years later the case caught Arthur Conan Doyle's attention. Convinced that an innocent man had been convicted and executed, he could never find the real murderer, but now, bestselling author Sinclair McKay has solved the case.