The fifth season of Murdoch Mysteries premiered on February 28, 2012, but earlier on September 27, 2011, CityTV (Rogers Media) announced that it would not be continuing the series beyond its fifth season. Season 5 was to be the series finale . . . until CBC had picked up the show and ordered a sixth season.
January 1899, Murdoch meets Jack London in the Yukon and evidence that the gold rush is nearly over. (ep.501)
On suspension for interfering in an investigation, and on the run for surreptitiously freeing a murderer to make amends, William Murdoch has left Toronto, and police work, for the Yukon in pursuit of solace and fortune and meets a man named Jack London. Back in the city, newly promoted Chief Constable Giles makes it clear to Inspector Thomas Brackenreid that he'll be keeping a very close eye on police matters. Meanwhile, Murdoch's beloved former associate, Dr. Julia Ogden, is now working alongside Acting Detective George Crabtree and Dr. Emily Grace, a feisty young protégé.
When Elvira Cummings (Alison Jantzie), a young opera singer, is poisoned during a rehearsal of La Bohème, Detective Murdoch suspects the intended victim was Madame Rosa Hamilton (Measha Brueggergosman), the diva who stormed off stage moments before her protégé collapsed.
When Detective Murdoch investigates the abduction of Lucille Messing (Tori Anderson), a shy, churchgoing librarian, he's stunned to discover his friend, Anna Fulford (Lisa Faulkner), working at the library under an alias. Murdoch has grave fears for her safety since the Black Hand, a criminal syndicate responsible for murdering her fiancé, still has a price on her head.
An argument after a hockey practice leads to Toronto hockey team captain Archie Simpson being knocked out by Eddie Driscoll, a bombastic and popular new player. Though he wakes from unconsciousness, he's later found dead in the locker room.
As New Year's Eve and the twentieth century approaches, Detective Murdoch is suspicious of Gideon Turner, who claims he has knowledge of soon-to-be-committed crimes but refuses to say how or why. When Turner bolts from police custody and thwarts a murder attempt, Murdoch, Inspector Brackenreid and Constable Crabtree demand to know where he got his information. He calmly explains he saw the events happen when he travelled to the future.