Every series detective must eventually meet his nemesis, a foe too powerful or clever to be disposed of in only one adventure. Holmes had Moriarty (though to be technical and pedantic -- two things I often am -- he was actually eliminated in the same story in which he was introduced, but there have been many sequels and prequels by other hands), Nero Wolfe had Arnold Zeck, Doc Savage had John Sunlight, Superman has Lex Luthor, Batman has The Joker and Ra's Al Ghul.
     William Murdoch, the constable from Toronto in the Murdoch's Mysteries TV series, has one, too (I could be wrong, but I don't think a comparable character exists in the books): James Gillies. That's good news for actor Michael Seater. who has played the part three times this year alone.
      Unfortunately, while a nemesis is supposed to define the hero, to show his greatness by defeating a worthy adversary, Gillies is showing Murdoch up to be a weak and ineffectual would-be hero. So far, Gillies has been stopped not so much by Murdoch's efforts as by Gillies' own flaws. The ease with which Gillies then escapes to plot against Murdoch again suggests that Gillies might be letting himself get caught so he can attempt to defeat Murdoch again.
     Gillies was introduced in the season two episode Big Murder on Campus as a sort of Leopold-and-Loeb thrill killer. He was belatedly re-introduced three years later when it was discovered he had faked his death in prison and escaped to seek revenge on the only man who out-thought him in Murdoch in Toyland. In the end, he disappeared while in police custody, returning with a more involved scheme to frame Murdoch's true love, Julia Ogden, for murder in Crime and Punishment, then to taunt Murdoch so he can put the detective in a death trap, supposedly forcing him to choose between suicide and saving Julia in The Murder Trap. Again, he is caught, and mention is made through several episodes of the following season to his trial continuing, his execution being postponed by appeals (his family is wealthy) leading up to A Midnight Train to Kingston. His fate is uncertain at the end of the episode, though it is presumed he has survived, and he is no doubt fated to return again.
     Frankly, he's pretty puny for a master criminal. His crimes were never personal or for profit; he just wanted to prove he was a super-man, better than everyone else. Murdoch puts a crimp in that, so he must destroy Murdoch.
     What makes Gillies so much less interesting than say Moriarty or Hannibal Lecter is not that he is insane but that he is barely functionally insane. How he passed for normal for so many years is a mystery because he is now a raving lunatic. Having escaped prison and the hangman's noose he is so insane that he neglects to seek his revenge from a distance and by proxy. He is always caught, after killing other people or causing them to be killed. He is so clever that after numerous escapes from custody, he still manages to escape from dedicated lawmen, including Murdoch.
     Gillies must go. He is too one-note to be interesting any longer. The producers would be well-advised to just let him die, let his lifeless body be found in a future episode, as when Vincent Donofrio's Goren discovered his nemesis on Law & Order: Criminal Intent was dead. Catharsis denied for the detective can be good for the viewer, particularly if it spares us another meeting with Gillies.