dinburgh, 1888. A violinist is murdered in his home. The dead virtuoso's maid swears she heard three musicians playing in the night. But with only one body in the locked practice room - and no way in or out - the case makes no sense.
Fearing a national panic over another Ripper, Scotland Yard sends Inspector Ian Frey to investigate under the cover of a fake department specializing in the occult. However, Frey's new boss, Detective 'Nine-Nails' McGray, actually believes in such supernatural nonsense.
McGray's tragic past has driven him to superstition, but even Frey must admit that this case seems beyond reason. And once someone loses all reason, who knows what they will lose next...