The Diamond Lake Monster.
There's a sucker born every minute.
The legend of the Lake Monster comes back to life as Nick and Hank investigate a mysterious sighting linked to a tourist's death at a local lake.
Rosalee's past comes back to haunt her, while Capt. Renard continues to support a candidate for mayor.
Elsewhere, Nick is shown the scope of the Wesen uprising as the secret government agency takes him into the heart of their Portland operations center.
This episode provides examples of:
- Call-Back: Tony, Rosalee's drug addict ex, sends her another letter saying he needs to talk to her. She tears it up angrily.Rosalee: I don't wanna deal with this!
- Chronic Backstabbing Disorder: Wayne Dunbar, one of the Luisnant-Pecheur brothers who run the boat hire. The idea to hire Logan Cobb to scare people and drum up business appears to be his, and he decides to keep doing it after someone dies because the notoriety has driven business up so much. Meanwhile, his brother Oliver wants to stop because things have got out of hand. When Cobb hears how well they're doing and wants more money, and Trubel comes around to scare the brothers, Wayne comes up with an elaborate plan for Cobb and Trubel to take each other out and take Oliver with them.
- Due to the Dead: Meisner reveals to Nick what Hadrian's Wall did with his mother's head: buried it, with her body, in a graveyard attached to their compound. He apparently provides Nick with photographic proof of this, but the audience don't see it.
- Elaborate Underground Base: After passing Eve's test, Nick is finally taken to Hadrian's Wall's base.
- Expository Hairstyle Change: Eve wears her hair in a simple, functional ponytail, echoing her functional, military new nature. Except when she goes out, when she wears one of her six differently-coloured wigs.
- Hoist by Their Own Petard: After trying and failing to get Logan Cobb, Trubel and his brother Oliver to all kill each other fails, Wayne Dunbar tries to escape arrest by diving into the lake, where he gets shot by a bunch of people hoping to catch the Diamond Lake Monster.
- Secret War: Hadrian's Wall are engaged in a secret global war against Black Claw, who want the world run by Wesen, for Wesen. HW want the Grimm gang on board. The gang are torn between mistrust stemming from some of HW's shady methods and desire to stop Black Claw. They decide they'll only join if they all agree.
- Stock Ness Monster: The Diamond Lake Monster. Actually a Wasser Zhane, a water-living Skalengeck variant hired by two brothers to drum up business for their lakeside shop/boat hire.
