In the episode, Nick and Eve struggle to fight against Zerstörer, who is also wanting to leave the other place and go to the real world to retrieve Diana for his own purposes.
Eve (Bitsie Tulloch) and Nick (David Giuntoli) are in the other place, after forcing to be wogue by Zerstörer ("Destroyer" in German) they try to fight him together.
Wu (Reggie Lee), Hank (Russell Hornsby), and Rosalee (Bree Turner) translate that the Zerstorer needs Nick in order to travel to present day Earth.
Monroe (Silas Weir Mitchell), Rosalee, and Eve figure out the stick they found in the Black forest is actually a long-hidden shard of wood from Zerstörer's powerful staff.
Zerstörer attacks the precinct, to get the stick back from Nick, killing several officers including impaling Hank through the throat and stabbing Wu in the stomach.
His entrance heralded by a flock of dead bats, diving through a mirror in Olympic style, human beings swatted away as if they were less than said bats, a flood of terrifying analogies in the Grimm diaries, Diana genuinely terrified for the first time in her young life: the sense of dread and impossible odds builds well over the episode’s run time.