A Wasser Zahne impersonating a lake monster kills a hapless tourist, and Nick and Hank are asked to help investigate the murder. The Wasser Zahne, Logan, was hired to impersonate the lake monster by two brothers, who rent boats to tourists, in order to drum up business.
The brothers, Luisant-Pechur Wesen, are unaware that Nick is a Grimm and is onto them. One brother, Wayne, asks Logan to kill another tourist to bring in even more macabre monster-hunting tourists. After Logan does so, however, he demands half of their income that they're earning off his murders.
Trubel pretends to be a mercenary Grimm out for the Wasser Zahne's head, and the brothers arrange for her to take care of their problem. Wayne, however, decides to double-cross everyone and asks Logan to kill his brother.
The confrontation goes somewhat awry, though Trubel easily bests Logan, killing him. Nick and Hank burst in and reveal that Nick is a Grimm. Wayne takes off out the back door, fleeing towards the lake. He forgets, however, that there are a large number of trigger-happy monster hunters out on the lake, and they soon fill the lake with bullets as soon as they see movement.
Meanwhile, Martin Meisner invites Nick to see what Hadrian's Wall is all about, and warns him that their conflict is world-wide. He asks Nick to join in their cause against Black Claw.