The story picks up right where it left off, as Nick regains consciousness after consuming the heart purification potion. Rosalee prepares an herbal tea for Juliette and Renard to consume, with three drops of blood from Nick as the final ingredient. When Juliette arrives home, she is shocked to find the floor of her house replaced with a massive abyss. Whatever Juliette drank is clearly having a very serious hallucinatory effect.
Later, Monroe pays a visit to the bank and finds himself in the middle of a Wesen robbery. He is shocked and horrified to discover that the Wesen are fully morphed during the heist, breaking a long-standing Grimm code of conduct in the human world. Monroe knows that this robbery is a game changer.
Nick brings Hank up to speed on the mysterious key. Apparently the key is one of seven in the world, and each has a piece of a map etched on its side. Together, these maps lead the way to a secret treasure that's been hidden away for centuries. Nick tells Hank about Renard's involvement as a Hexenbiest and member of a royal family. Nick vows to wear the key around his neck from now on; if someone wants to take it, they'll have to kill him first.
Nick and Hank arrive at the bank to investigate the crime. It's clear all the people in the building assumed the robbers had intricate masks on... but their naivete won't last long. Monroe tells Nick that the robbers broke the Code of Swabia - the most important law in the Grimm world. Bad things happen when Wesen use their identities for personal gain.
Monroe scopes out the Junkyard Dog Bar, a dicey Wesen hangout, in hopes of tracking down the perpetrators. Monroe discovers that the criminals are there, but they remember him from the bank before he has a chance to act. A massive fight breaks out, but Nick and Hank can't bring the robbers in without any charges. They do learn the robbers' names: Cole, Krystal and Gus.
The next day, the Wesen strike another bank, this time upping the stakes by killing two bystanders during their escape. Back at Monroe's, Nick listens as Monroe tells him about the Wesen Council. They take breaches of conduct very seriously, and the typical penalty is death. Before the conversation goes any further, Nick is called to the latest bank's crime scene.
At the Spice Shop, the local Wesen community has congregated and wants answers regarding the rogue Wesen. They're all convinced the human population will find out soon enough. Rosalee tells them all to go home - this will be over soon. Rosalee later tells Nick about her "uneasy alliance" with the Council. She has a contact, and it's Rosalee's duty to call them about the robbery.
At the robber's hideout, Gus has grown fearful and antsy and no longer wants to be a part of the heists. But Cole won't have it and puts Gus in his place by beating him to a pulp. Krystal gets involved in the fight and kills Gus on her own - it will just be the two of them from here on out.
Nick and Hank track down Cole and Krystal to their warehouse and apprehend the pair after a heated shootout. Both robbers are confident that the charges will be dropped - there's is no evidence pinning them to the crimes. But as they're led through the station, a hit man from the Wesen Council pulls a gun and shoots both suspects dead, clearly a consequence of Rosalee's phone call. While the others are baffled, Nick knows that justice has been served in the Grimm world.