In the episode, Nick and Eve go inside the mirror to find the other place to be a resemblance to the Black Forest with some slight differences.
Nick (David Giuntoli) arrives at the loft and talks with Adalind (Claire Coffee) about Renard's (Sasha Roiz) knowledge of Diana's (Hannah R. Loyd) danger (due to those symbols).
Monroe (Silas Weir Mitchell) and Rosalee (Bree Turner) return home and find the Hexenbiest book open, marks/blood on a new full-length mirror and Eve (Bitsie Tulloch) gone.
They call Nick to help them find Eve, deducing she crossed the mirror and just then, the book magically locks itself and only Adalind can re-open it.
Zerstörer shows knowledge of Nick's Grimm powers and has his staff shine as Eve woges into her Hexenbiest form.
The episode was viewed by 3.96 million people, earning a 0.8/3 in the 18-49 rating demographics on the Nielson ratings scale, ranking third on its timeslot and sixth for the night in the 18-49 demographics, behind Dr. Ken, Dateline NBC, Last Man Standing, Truth and Lies: The Family Manson, and an NCAA Tournament.
"[3] Kathleen Wiedel from TV Fanatic, gave a 3.2 star rating out of 5, stating: "While this episode wasn't terrible, it really amounted to a whole lot of exposition that should've already happened and an encounter with a big bad that could've been reached in the first five minutes.
"[4] Sara Netzley from EW gave the episode an "A−" rating and wrote, "When you step through a mirror into an unknown world, isn't it common courtesy to leave a note?
"[5] Christine Horton of Den of Geek wrote, "This is the first of a two-parter, and we're left with Nick and Eve in a face/skull-off with the Zerstörer, who seems immune to both of their powers.