Ep 18. Cat and Mouse

Nick Burkhardt, a homicide detective, discovers that he is a descendant of an elite group of hunters known as "Grimms". These hunters are tasked with maintaining the balance between humanity and mythological creatures, known as "Wesen". In season 1 episode 18 titled "Cat and Mouse", Nick discovers a plot to steal rare coins from a predatory lender, who also happens to be a Wesen.

The episode begins with Nick and Hank investigating a string of burglaries that have recently occurred in the area. They discover that a group of robbers has been breaking into the homes of wealthy individuals, stealing rare coins and other valuable items. Nick recognizes that the coins are not just valuable to their owners, but also to the Wesen community. He suspects that the Wesen are involved in the thefts, but has no proof.

Meanwhile, Juliette, Nick's girlfriend, is volunteering at a pet adoption center when she meets a stray cat named Adalind. The cat is not just any ordinary cat, as Juliette soon discovers. Adalind is actually a Hexenbiest, a powerful and dangerous Wesen. Juliette, being a veterinarian, decides to take Adalind in and care for her.

As the investigation continues, Nick and Hank discover that one of the burglars is a Wesen, and they manage to capture him. The Wesen, named Bucky, agrees to cooperate with the detectives in exchange for a lighter sentence. Bucky leads Nick and Hank to the location where the stolen coins are being kept, but when they arrive, they discover that the coins have already been stolen by someone else.

Nick and Hank suspect that the person responsible for stealing the coins is the predatory lender, Leo Taymor, who is also a Wesen. They pay him a visit and confront him about the thefts, but he denies any involvement. However, they notice that Leo's house is filled with rare coins, and they realize that their suspicion was correct.

Leo is not just any ordinary Wesen, he is a Fuchsbau, a type of Wesen with fox-like characteristics. He is cunning and sly, and he manages to evade capture by Nick and Hank. Leo realizes that he needs to get rid of the evidence, so he hires a group of mercenaries to break into his house and steal the coins.

Nick and Hank manage to get a lead on the mercenaries and track them down to a warehouse. They find Leo there as well, and a fight breaks out. Leo transforms into his Wesen form and tries to escape, but Nick manages to catch up to him. In the end, Leo is arrested and the stolen coins are returned to their rightful owners.

In the subplot, Juliette discovers that Adalind is a Hexenbiest when Adalind transforms in front of her. Juliette is shocked and scared, but she decides to give Adalind a chance. She hopes that Adalind can change her ways and become a good Wesen. However, Adalind has other plans. She intends to use Juliette to get revenge on Nick.

Overall, season 1 episode 18 of Grimm is a thrilling ride that combines detective work, supernatural elements, and plenty of action. The episode highlights the complex relationship between humans and Wesen, and the difficulties in maintaining a balance between the two. The subplot involving Adalind adds an extra layer of intrigue and sets up future conflicts for the series.