The blood-dimmed tide is loosed, and everywhere the ceremony of innocence is drowned.

A ship docks in Portland Harbor and a security guard, Yates, is patrolling onboard when he hears something in the hold. He hears something moving in a cargo container and investigates, and finds blood seeping out of the door. He calls in two harbor patrolmen and the three men open the container. The interior is strewn with corpses and the walls are covered in blood as well as writing. A cat-like creature leaps out of the shadow and attacks them

Kelly Burkhardt approaches her son’s home and watches as Nick fights Kimura, the Dragon Tongue assassin. Nick subdues Kimura and turns on Kelly when she comes in, but she manages to drug Kimura unconscious when he tries to kill her son. Kelly then informs Nick of who she is.

At the docks, the cat-creature from the cargo hold, a Mauvais Dentes, changes to human form and leaves, stepping over the three fresh corpses.

Nick wonders how Kelly can be alive, but she ignores his question for the moment and rips open Kimura’s shock, revealing tattoos across his back. Nick says that he could see Kimura for what he really is, a Wesen, just as the police pull up outside. He starts to tell his mother to leave but discovers that she’s already slipped away. Renard and Wu bust in with a squad of policemen and Renard notices and recognizes the tattoos on Kimura’s back. As the officers cuff Kimura, Renard comments briefly on how Rick took the man out and then asks where Juliette is. Nick explains that she’s at the hospital in a coma. When the captain suggests that Nick check on her, Nick says that he would if he could help but there’s nothing he can do.

At the apothecary, Rosalee and Monroe are testing the cat that Adalind used to infect Juliette. When Rosalee’s test is inconclusive, she tells Monroe that they have to talk to Nick.

As Renard checks out the house, he notices a crossbow bolt imbedded in the wall. After he leaves, Kelly slips back in and say that she needs to interrogate Kimura. She explains that she’s been following him for a long time and that he’s the only surviving Wesen who knows who betrayed the Burkhardts. When Nick wonders if his father is alive as well, Kelly explains that his father died. The woman in the car was her friend Gina Serafini, and Kelly sent the two of them away when the killers came after her. The police mistakenly identified Gina as Kelly because the killers took Gina’s head and the rest of the body was too badly burned for positive ID. To protect Nick, Kelly and her sister Marie agreed to let Kelly remain “dead. When Kelly tries to touch Nick reassuringly, he flinches away.

Rosalee and Monroe arrive and scent Kelly, who attacks them when they revert to their Wesen forms. Nick manages to separate them and explains that the Wesen are his friends. They tell Nick that as part of her condition, Juliette is losing her memories. They have to stop that before they can come up with a cure or there’ll be nothing left of Juliette even if they save her life. Nick tells them to do what they have to and they cautiously back out, eying Kelly.

At the hospital, Renard inspects the comatose Juliette and confirms that her eyes have turned black.

Kelly finds a photo of Nick and Juliette together and asks how long they were together. Nick angrily asks where she’s been and his mother explains that she set out to avenge her husband’s death. However, the trail lead her far afield and she learned that the Seven Royal Families were attempting to reestablish their power. Nick already knows about the Verrat and Kelly, impressed, wishes that she could have taught him herself. She also knows that Nick has the three coins and says that he should hand them over so she can protect them.

Renard visits Catherine, Adalind’s mother, and demands to know where he can find her daughter. He tells Catherine about Adalind’s revenge on Juliette and says that she shouldn’t have interfered why. Catherine doesn’t understand and Renard explains that he wants to keep Nick in Portland under his control. If Juliette dies, Nick could leave. Renard warns Catherine that he’ll hold her personally responsible if Juliette dies and walks out.

At the hospital, Juliette remembers her dinner with Nick and Monroe, but the memories start to fade as she forgets what Nick’s face looks like. Meanwhile, Nick sits at her bed watching.

At home, Hank is barricaded in his room holding a shotgun. As he remembers seeing Monroe in the woods, he takes pills to stay awake.

The next morning, Kelly makes breakfast for Nick without much luck. The station calls to tell him about a case and, as he starts to leave, asks hi smother if she’ll be there when he gets back. Kelly assures him that she will and Nick heads to the docks. An exhausted Hank is waiting for him and assures his partner that Juliette will pull through. As they talk, the Mauvais Dentes in human form watches them from the crowd. Aboard the ship, Wu shows the detectives the cargo container and the corpses. Nick sees a drawing of a scythe on the wall and tells Hank that the container was used to lock something in, not out.

When they return to the station, Nick and Hank confirm that the ship belonged to a holding company and they check with the French police. Two FBI agents, Kanigher and Durwell, arrive to take over on the case and Renard tells his detectives to cooperate. Nick and Hank hand over their notes and Nick starts to suggest they stay involved. Kanigher turns him down and Renard interrupts before Nick can push it further.

Later, Renard goes down to the cells to check on Kimura. He informs the Wesen that he’ll be arranged, convicted and executed in short order. The captain says that he knows who Kimura is working for and the Wesen casually informs a surprised Renard that there are two Grimms in Portland.

Nick returns home and discovers that Kelly has been cleaning up. He takes her to Marie’s trailer and she explains that it belonged to her and her sister. Kelly tells her son that being a Grimm is inherited and that she found out when she was 10 and suffered nightmares. Her grandfather trainer her and Marie, taking them out on hunts, and Kelly admits that she didn’t want the same life for Nick. Nick gets her the coins and Kelly says that she’ll take them to the island where they were forged so that they can be destroyed. As she starts to leave, Nick says that he can’t judge her decisions but wishes she had been there as he grew up. He asks her to look at the photos of the cargo container and identifies the scythe as the symbol of the Reapers. Kelly knows that Nick has fought and killed two of them and sent their heads to Mannheim. They both agree that the killer was something else and Kelly checks the journals, finding a sketch of a Mauvais Dentes. She then tells Nick to hide the coins again because she needs to examine the bodies of the creature’s victims.

At a castle in Europe, one of the Royal Family members is torturing a resistance member for information. The Mauvais Dentes calls him and says that he’s seen Nick and that he’ll dispose of the Grimm and call back when he’s done.

Catherine goes to Rosalee’s apothecary to shop for supplies. When Rosalee says that she’ll need a few days to get one ingredient, Catherine reveals herself as a hexenbiest and tells her to get it sooner, and Rosalee says that she’ll do what she can.

At the morgue, Kelly finds a puncture wound in the corpse’s neck and tells her son that the tooth mark is that of a Mauvais Dentes. She warns Nick that it stalks its victims like a cat and will try to lure him in. Monroe calls and tells Nick about Catherine’s visit, explaining that she left her phone number but not her name or address. Rosalee has confirmed that the ingredients are the ones she needs to cure Juliette and they give Nick Catherine’s phone number so she can trace it.

Catherine returns home and calls to tell Renard that her daughter has disappeared. She tells him that she can make a cure but needs someone specific to administer the antidote. As Catherine hangs up, Nick barges in searching for Adalind. Catherine realizes that Nick was the one who stripped Adalind of her powers and tells him that she doesn’t know where her daughter is and has no reason to protect her. Nick tells her to find Adalind and goes outside where Kelly is waiting. They figure that Catherine wasn’t involved in the attack on Marie and Kelly confirms that Marie gave Nick the key before she died.

Renard calls a mysterious ally on phone and tells him that there are two Grimms involved and he plans to stop them from getting to Kimura. He then assures his partner that he’ll take care of things.

At the trailer, Nick and his mother examine the key. She takes out a hidden page from the diary of one of the first Grimms and explains that the Seven Royal Families forged seven keys during the Crusades. The keys contain a map which leads to a vast treasure that the Families took during the sacking of Constantinople. The Grimms worked for the Seven Families, keeping their Wesen warriors in line, and the Families cut the map into seven pieces and gave them to seven different Grimm knights. Among the treasure is an unknown relic of vast power that can give the families control of the world. Kelly figures that the Seven Families know that Nick has one of the keys and wants him dead. When he wonders how they can know that when he hasn’t told anyone about the key, Kelly warns that someone in Portland must have found out, and they need to interrogate Kimura and find out who it is.

A guard serves Kimura his meal and when the Wesen eats it, he collapses, dead.

The Mauvais Dentes goes to a lumber mill with the truck he stole from the security guard. He then calls Kanigher anonymously and tells her where she can find it. When Kanigher and Durwell arrive, they find the Mauvais Dentes waiting for them. Once Durwell gets close enough to handcuff him, the Wesen transforms and kills him.

When Nick gets to the station, he discovers that Kimura is dead and goes out to his car to tell Kelly. Kanigher calls him and explains that the Mauvais Dentes has killed her partner and will kill her as well if Nick doesn’t come to the lumber mill alone. As they drive to the mill, Kelly warns Nick that it’s a trap and that their opponent will somehow find a way to get close enough to Nick to surprise and kill him. When they arrive, the two Grimms split up and enter the mill. Nick finds a trail of blood and follows it to where the two FBI agents’ corpses are lying on the ground.

As he examines the bodies, Monroe calls and tells him that they have the cure, but it’s unstable. If they don’t get it to Juliette within 45 minutes, it will become useless and they’ll have to start again. Nick tells Monroe that he’ll meet them at he hospital and turns to go… and the Mauvais Dentes, disguised as Durwell’s bloody corpse, attacks him from behind.