A summer heat wave finds much of Toronto taking refuge at the beach, including Inspector Brackenreid and Dr. Ogden, but when a body marked by a large bite washes ashore, rumours of a lake monster quickly spreads across the city.
Detective Murdoch investigates the death of Katie Buchanan who is found dead at the beach by her friend Elaine Lawson. Both are entrants in a beauty pageant known as the "Miss Purity" competition, to select the new face of Alexander soap. Dr. Ogden, who is spending her day off at the beach finds what appears to be a large animal bite on the woman's torso.
Katie's boyfriend, James Bennett, had recently left her for another competitor, Marie Nicholson and becomes a prime suspect. Inspector Brackenreid however is certain he saw a monster in Lake Ontario while Murdoch is skeptical until he too sees a creature in the water. Constable Crabtree is dismissive of any suggestion that there might be a monster in the lake and thinks it's far more likely that one of the Miss Purity contestants is involved. "It's quite a prize, and women can be very competitive."
Tropes:
- Arbitrary Skepticism: Constable Crabtree is completely convinced that there cannot be a monster in Lake Ontario, despite the fact that he has a long history of believing in just about every paranormal and science fiction idea he's been presented with, from aliens to black magic to ghosts.
- Beach Episode
- Childhood Friend Romance: Katie Buchanan and James Bennett were childhood friends who had been inseperable since an early age; their relationship seemed just destined to be. This makes it very strange when James suddenly dumps Katie for Marie Nicholson.
- Death by Irony: Marie Nicholson claimed that she was pregnant by James Bennett to force him to abandon Katie Buchanan, which led to Katie committing suicide. James promptly tells the head judge of the Miss Purity competition of Marie's pregnancy and gets her thrown out, which leads to her angrily revealing she had been lying about being pregnant to ensure Katie would drop out of the contest in grief. Devastated to learn that the love of his life has killed herself over a lie, James stabs her to death with an icepick in a fit of rage.
- Irony: For once, Crabtree is the skeptical one, with Murdoch, Breckenreid and Julia all eagerly pursuing the angle of the lake monster being real. An incredulous Brackenreid points out that this means Crabtree believes in zombies, werewolves, vampires, Martians, Venusians, curses, voodoo, ghosts, and, apparently, sea monsters, but not a creature in Lake Ontario, that both the Inspector and Detective Murdoch have witnessed.
- No More for Me: In the opening, Brackenreid's first look at the "monster" convinces him to set down his bottle of ale.
- Right for the Wrong Reasons: Crabtree explains he believes that the sea monster is fake because "he can't imagine something so dastardly living in fresh water". He's right about it being fake, but as a certain other series reminds us, fresh water has more than its fair share of deadly killers.
- "Scooby-Doo" Hoax: It turns out that the lake monster is an artificial construct made by the grumpy local hermit, who just wanted to scare people away from his land. When Katie committed suicide despite his efforts to save her, he decided to use one of his man-traps to simulate a bite-mark and show off his fake lake monster to finally put it into action.
- Shout-Out: The plot of this episode is very similar to the plot of Jaws, with the exception that the monster is fake.
