Murdoch Mysteries - Season 3 Episode 2 The Great Wall Forensic sleuthing in the age of invention.
Overview: Murdoch is called to Station House Five when a decorated constable is murdered and the local detective is ill. Murdoch finds that everyone is ready to blame an elderly Chinaman named Fong Choy because of something to do with his granddaughter, but she is nowhere to be found and Fong Choy won't talk.