Season 1 of Murdoch Mysteries first premiered on CHMI, the Winnipeg station of Citytv on Sunday, January 20, 2008; the rest of the Citytv stations broadcast the series on Thursdays, beginning on January 24, 2008.
Toronto City council are entertaining the idea of abandoning direct current electricity for the city in favour of the new alternating current. At a public demonstration on the dangers of alternating current in which a dog was to have been electrocuted it is instead Alice Howard, the newly crowned Miss Toronto Electric and Light, who is killed when she pulls the handle on the switch. Constable Crabtree believes that the representative of the Toronto Humane Society might be involved. Detective Murdoch asks Nikola Tesla, who also witnessed the electrocution, for his help.
Professional boxer Amos Robinson is shot after a fight and his wife Fannie is charged with murder. Having studied the blood on Mrs. Robinson's dress Detective Murdoch is convinced that she simply held her husband as she claims and he begins to review events to learn who had motive to kill Amos.
Sir Arthur Conan Doyle (Geraint Wyn Davies), who is in Toronto to make a speech on spiritualism, invites Detective Murdoch to a seance hosted by Miss Sarah Pensall (Maria del Mar) where they are told of the location of the body of Miss Iris Winston. Detective Murdoch, despite his disbelief in communication with the dead, goes with Sir Arthur go to the location and finds Miss Winston murdered.
Shortly before his wedding Wendell Merrick is found murdered in the church. In investigating the murder Detective Murdoch discovers that the marriage was a sham to claim an inheritance and that Mr. Merrick was homosexual. When Mr. Merrick's lover is also found dead by suicide Detective Murdoch discards jealousy as motive and looks to a larger suspect pool.
When the body of John Delaney is found in the woods shortly after he had argued with a drunkard who claims a dog fight was fixed when he lost a lot of money Detective Murdoch gets the case and discovers that his father is the prime suspect. Harry Murdoch (Stephen McHattie) admits that he was no friend of the victim but is adamant that he didn't kill him. Detective Murdoch believes that his father is responsible for the death of his mother and doesn't entertain his father's claims of innocence with the same vigour he would with someone else. With the help of an idiot savant who has a fixation for time, Detective Murdoch establishes a time-line which clears his father.
When a partially decomposed body falls onto the stage of the Grand Theatre during a performance of Macbeth Inspector Brackenried is startled. The body is identified via dental records as that of Virgil Smart, the owner of the theatre prior to his death a year before. With Mr Smart having known to be dead they exhume the body previously believed to have been Mr Smart. Dr Odgen does a facial reconstruction to identify the man in the grave. In questioning the players about the death of Mr Smart Detective Murdoch realises that their recollections and accountings are rather detailed and similar for an event of more than a year previous. Constable Crabtree finds a hidden room in the theatre.
Richard Hartley, the newest member of King's Rowing Club's eight man team is found dead. Detective Murdoch discovers that Mr. Hartley had replaced Horace Briggs, an employee of the club, on the team. Dr Ogden concludes from the autopsy that Mr. Hartley was drowned but that he was also beaten. When his attempts to question the members of the team prove unproductive Detective Murdoch develops a lie-detective device to help sort out the truth from all of the lies and misdirection.
Sir Arthur Conan Doyle (Geraint Wyn Davies) is again in Toronto wanting to study Detective Murdoch for a new novel he is writing. Detective Murdoch investigates the murder of Rod Grimsby but is troubled by the confession of the victim's son Harcout, a ventriloquist, via his puppet Mycroft.
The murder of industrialist and philanthropist Howard Rookwood appears to have been done by a child or group of children. Mr. Rookwood was a supporter of Baker House which specialised in housing Home Children in the Toronto area.
A robed and hooded person begins killing people at the Greyson Institute, a facility which specialises in researching brain function. Detective Murdoch gets the case and is disturbed when Miss Sarah Pensell (Maria del Mar) tells him that she has seen the murders in a vision and that one of the future victims is Detective Murdoch.
The Queen's grandson, Prince Alfred (Chad Connell), is in Toronto and Detective Murdoch and Constable Crabtree are assigned as his police security, a task which is complicated by the prince being a bit of a partier who enjoys the company of many women. When a woman with tattoos indicating a connexion to the Irish Republican Brotherhood is found dead in a park everyone believes that there is a plot to harm the prince while he is in 'the colonies'.
When Henri Gaston is found in the upper limbs of a large tree in a farmer's field and there are no footprints in the freshly ploughed soil. Detective Murdoch and Constable Crabtree are perplexed. Constable Crabtree thinks that Martians might be involved. When he learns that Mr. Gaston had refused to sell his land, Detective Murdoch turns his attention to more human suspects. After getting close to solving Mr. Gaston's murder, Inspector Brackenreid informs them that they are to cease all investigation in the matter under penalty of death by hanging for treason.