Thanks to Captain Renard, as far as Adalind knows, the Royals have kidnapped her baby. Desperate to get her daughter back, she quickly exhausts all available options for help. Her first stop is Nick's house. Nick (David Giuntoli) and Juliette play dumb, assuring Adalind that there's nothing they can do to help her. If Adalind ever finds out that Nick's mother has her baby, she'll never stop searching for them.
Adalind buys Nick and Juliette's act and heads to Renard's condo for a quick face-slapping. She'll never forgive him for his betrayal. Unfortunately, Renard can never tell her the truth. Next, Adalind heads to the only other Portland residents she knows: Monroe and Rosalee, who also play dumb. Rosalee tells Adalind that she can stay as long as she wants, and Adalind quickly falls into a deep, much-needed sleep.
Meanwhile, on the outskirts of town, a drifter (Jacqueline Toboni) makes her way toward the city limits. A pickup truck stops nearby and two Wesen ruffians try having their way with the young girl. The next morning, Nick and Hank arrive at the scene to find two dead Wesen. The crime scene doesn't make sense, though: the victim became the attacker and dispatched two formidable foes, but who is this mystery vigilante?
Sergeant Wu uses a single French fry to procure security footage of the suspect at a local fast food joint. It's a 21-year-old girl, certainly not the suspect they thought they'd be dealing with. Later that day, another call comes in: a stabbing victim was found in a local park. Recognizing the M.O., Nick and Hank race to the scene, bringing Monroe along for a Wesen angle on the situation.
Wu receives a call that someone has spotted the suspect at a hostel nearby. Nick, Hank and Monroe head to the establishment and find the girl outside. When Nick and Hank attempt to apprehend her, Monroe makes a shocking discovery: she's a Grimm!
Nick takes the girl, Theresa Rubel (who goes by the name Trubel), to the police station while he figures out what to do about the situation. In Trubel's backpack, he finds a notebook with Wesen scribbles and notes in it. It's eerily similar to his book in the trailer. Upon questioning Trubel, Nick realizes that she has no idea what she is. He'll need to introduce Trubel to the entire Wesen world.
Nick and Hank take Trubel to the trailer, where he shows her his own book. Trubel is astounded and strangely relieved. She's spent her entire life thinking she was crazy, but now Nick is confirming that she's not insane. What she's suffering from is not an affliction, but rather a rare and powerful gift. Nick has a lot of explaining to do, and Trubel couldn't be more eager to learn everything he has to teach her. It looks like Nick has a new Grimm partner.