When a flying machine crashes, killing a man on the ground, Murdoch's investigation uncovers high-level conspiracy and sabotage in the race to achieve the first human-controlled flight.

When an anonymous madman threatens the citizens of Toronto with a deadly toxic gas, Murdoch must race against the clock to stop him.

Detective Murdoch investigates the death of Peter Farrelly who had a loud altercation with someone the night before his body was found. Dr. Grace determines he was beaten to death. She also found chloral hydrate in his system - a bottle of which they found in the victim's luggage. They believe both the victim and his killer are from Newfoundland and so Murdoch and Crabtree head off to St. John's in the hopes of finding the suspected killer Ezekiel Farrelly. Crabtree was actually raised in St. John's by several aunts who, it turns out, have an interesting occupation. The solution to murder lies with finding an old pirate treasure map.

While investigating a mysterious death in Markham, Det. Murdoch discovers a hidden ornate and booby-trapped laden building that could contain the Holy Grail.

As the local temperance movement's crusade for local prohibition gains momentum, an opposing politician is found dead after an incident at a drinking establishment.

As Murdoch investigates the strange death of a footballer, Brackenreid gets caught up in the team's run to the Olympics.

Murdoch investigates a surgeon whose cutting-edge organ transplants wreak medical havoc and run afoul of Mary Baker Eddy and The Christian Science movement.

A spate of murders staged as suicides leads Murdoch to suspect a sequential killer targeting the elderly.

Crabtree and Constable Brackenreid go undercover at a boys school to solve a disappearance.

Murdoch investigates a car accident and uncovers sinister motives.

After obituaries are published in advance of two men's deaths, Murdoch discovers more intended victims, including Detective Watts.

Murdoch investigates a murder surrounding vaudeville entertainers Harry and Al Jolson. Detective Watts learns more about his own family history.

Murdoch helps a man look for his missing wife; Crabtree contemplates his relationship; the team from Station House No. 4 works on a murder case.

After a telephone call reports a body has been discovered, as well as reports of gunshots have been reported, Murdoch and Crabtree find an unlikely suspect cowering near the body. Murdoch suspects the true killer is still out there.

When a wealthy, high society couple is found drowned in their pool in an apparent double suicide, Murdoch suspects murder.

Inspector Brackenreid travels to St. Marys to help an old flame whose daughter is missing, and he happens to learn then that he is her father.

Murdoch helps a detective recover a ship loaded with antiques. Brackenreid considers leaving.

Crabtree and John are transporting a convicted axe murderer to prison when she escapes to exact revenge on those who testified against her.

As Murdoch seeks a promotion, a constable is shot in a botched raid on an opium den led by Watts.

Murdoch suspects John is being framed for murder by Inspector McWorthy and Brackenreid goes after the corrupt copper.

An actor is killed during a play featuring John Brackenreid and attended by Murdoch, Ogden, Crabtree, and John's parents.

Inspector Brackenreid learns that his youngest son, Bobby, is wanted for murder, while the Murdochs and Crabtree suspect old enemies are returning to harm them.

Murdoch investigates the suspicious death of a stage manager after a going away party for Mary Pickford.

Crabtree and John are transporting a convicted axe murderer to prison when she escapes to exact revenge on those who testified against her.

As Murdoch seeks a promotion, a constable is shot in a botched raid on an opium den led by Watts.

Murdoch helps a detective recover a ship loaded with antiques. Brackenreid considers leaving.

Murdoch investigates the suspicious death of a stage manager after a going away party for Mary Pickford.

An actor is killed during a play featuring John Brackenreid and attended by Murdoch, Ogden, Crabtree, and John's parents.

A spate of murders staged as suicides leads Murdoch to suspect a sequential killer targeting the elderly.

Murdoch suspects John is being framed for murder by Inspector McWorthy and Brackenreid goes after the corrupt copper.

Inspector Brackenreid travels to St. Marys to help an old flame whose daughter is missing, and he happens to learn then that he is her father.