Set in 1895 Toronto, Murdoch Mysteries explores the intriguing world of William Murdoch (Yannick Bisson, Sue Thomas F.B. Eye), a handsome young detective using radical forensic techniques, like fingerprinting and trace evidence, to solve some of the city's most gruesome murders. Though his unconventional approach elicits ridicule from fellow officers and scepticism from his boss, Inspector Brackenreid, Murdoch is often the only one who can crack the case.

Murdoch’s small circle of confidantes includes pathologist Julia Ogden, a staunch ally who shares the detective’s fascination with forensic science, and Constable George Crabtree, Murdoch’s eager but inexperienced right-hand man. Both are valuable allies who help Murdoch solve his varied cases and traverse the many strata of Victorian society.