To kill Koschei the Deathless, first you must find his soul, which is hidden in an egg, in a duck in a lead chest buried beneath an oak tree.
A girl is jogging alone in the woods when another man comes up fast behind her. She increases her pace, nervous that he plans to attack her. Nick easily passes her by, says good morning, and continues on.
Juliette is at home when she gets a call from an old friend, Alicia. Alicia says that she's leaving her husband Joe because he's abusing her physically and she can't take it anymore. Juliette insists that she come to Portland and stay with her. Nick arrives and Juliette notices that he's not sweating, and he admits that it's weird but doesn't seem particularly concerned. She tells him about how she invited Alicia and admits that her friend is too scared to report Joe to the police. Nick agrees but tells Juliette to make sure that Alicia doesn't tell Joe where she's going.
In Vienna, Renard meets Adalind at a café while his associate Meisner watches them. He pretends to like her for the benefit of any unseen observers and then they get down to business. Adalind asks about the cameras that Renard warned her about in his note and he suggests that his own family is responsible since they're the ones providing her with the room. He then tells her that he knows she is pregnant and asks who the father is, but she avoids the question. Renard warns Adalind that she will have to choose sides once her pregnancy becomes common knowledge, and suggests that she consider him a friend since no one else will be interested in her, only the child.
Boris Myshkin and his wife Olga are at the home of a rich sponsor in Portland, and Boris carefully examines a mother's sick daughter who has come to him for healing. She prays for deliverance and Boris touches her, his eyes glowing green. He tells her that everything will be okay and then collapses, gasping for breath. Olga gets him some tea and Boris tells the girl that the pain will stop in a few days. When she asks how much she has to pay him, Boris tells her that her living a long happy life is payment enough.
In a hotel room, Alex Ivenko receives a call and is told that a party will be happening that night. He gets the restaurant's address and tells the caller that they will pay "him" back then.
That night, Boris is at a restaurant being feted by the owner Dmitri. Boris flirts with the women, much to his wife Olga's dismay. Dmitri offers a toast to Boris and his healing abilities, and everyone joins in. Once Boris thanks them, he goes to the restroom via a storeroom and Alex, dressed as a waiter, attacks him. Boris manages to hold him off and grab his wrists, and Alex screams in pain as Boris transforms into a Wesen with transparent skin and glowing green veins. Boris then throws Alex out the window into the alley below. The man runs off but when he gets to his street, he discovers black marks on his wrists where Boris touched him. Alex gets to his hotel room and tries to call his contact, but passes from the pain.
Alicia finally arrives and Juliette makes sure that Joe didn't follower her. Nick promises Alicia that they'll take care of her. As Juliette goes to get her friend a glass of wine to settle her nerves, Juliette breaks into tears and Nick sees her briefly transform into a Fuchsbau.
The next day, Hank is having his final session for his injured leg with a physical therapist. Zuri. She assures him that he's fully recovered and Hank invites her out to dinner. Zuri looks nervous and tells him that she's been trying to keep everything professional between them.
A prep cook at Dmitri's restaurant goes into the walk-in freezer and finds a corpse in the back.
Nick meets Renard upon his return and the captain explains that he dealt with the Verrat while he was in Europe. He doesn't go into all the details of what happened but warns Nick that the Royals consider both of them a great threat. Hank arrives to tell them that they have a case and they go to Dmitri's restaurant. Wu tells them that the dead man is Ivan Markov, a waiter working at the restaurant. His waiter's uniform is missing and they find bruising on the man's Wu has found signs of a struggle in the storeroom. They realize that a fight occurred and ask Dmitri who was there the previous night. The owner says that Mila Guryanova, a local Russian woman, booked the restaurant for a private party and gives the detectives her phone number. He also turns over the surveillance camera footage.
Back at Renard's office, the partners review the footage with Renard and point out how Alex, wearing Ivan's uniform, went into the storeroom and then attacked Boris. Renard says that he's heard of Boris by reputation, and wonders why Boris didn't report the assault. Nick figures that the killer will try again and they go to see Boris, and Renard insists on going with them.
Alex is getting steadily worst as the black burns on his wrists spread across his body. He calls his contact and says that Boris has called him, and tells her to be strong. As he hangs up, Alex discovers that his teeth are falling out.
At Mila's home, a maid, Larissa Komarov, brings some fresh towels to Olga's room and finds the older woman crying. Olga is angry at her, knowing that she is one of Boris' lovers, and warns the maid that Boris doesn't care for any of them. As Larissa leaves, Olga briefly loses control and transforms into her Malin Fatal Wesen form.
As the detectives pull up to Mila's home, Renard explains that healers like Boris are revered in Russia, but Hank figures that Boris is a conman. Larissa ushers them in and Mila asks what is going on. Olga arrives and says that her husband is doing a healing but can't be disturbed. Renard insists and Olga reluctantly takes them to her husband. Boris is healing a young boy with an infected wound, and Nick sees him in his true Wesen form. Boris collapses after healing the wound and the boys' father thanks Boris. Once father and son leave, Renard explains why they're there. Boris and Olga discuss whether to tell the truth in Russian, and Renard speaks up in the same language, telling them that the police in Russia are useless. The Russian says that he has nothing to hide and says that he never saw Alex before. When Nick wonders why someone would want to kill him, Boris admits that he has many enemies: people he has failed to heal, and people who are jealous of his abilities. He says that he threw Alex out the window and Renard says that they'll patrol the area, and tells Boris to call if he learns anything new.
As the three officers leave, Larissa asks Renard if Boris is in trouble and he tells her that he isn't. Once they're alone, Nick tells his friends what he saw and Renard realizes that Boris is a Koschei, a Wesen with a gift for healer. His mother dealt with one when she and Renard were in Russia. The Koschei needed a potion to suppress his sex drive, which went into overdrive when he used his healing abilities. Renard says that he'll call a few people in Russia and find out more.
A hotel maid goes into Alex's room and finds the sheets covered in blood. She hears water running in the bathroom and discovers Alex, apparently dead and covered in radiation burns, soaking in the tub.
Monroe meets Nick and Hank at Aunt Marie's trailer and they go through the Grimm journals. The trio finally find a reference to a British Grimm discussing a plan to assassinate Rasputin, the Mad Monk. According to the letter the Grimm files, Rasputin is a Koschei, capable of healing himself and others, making it very difficult to kill him. The Koschei can also inflict death with a touch. When guns and poison didn't work, the assassin finally had to beat Rasputin senseless and then dump his corpse into a frozen river. The partners get a call about the hotel room and leave.
Renard calls his contact in Russia, Grigori, and Grigori confirms that the Royals still control Moscow and leave them with scraps. He informs Renard that Boris is a former assassin for the FSB who managed to kill his victims using radiation poisoning, but no one ever learned how he did it.
When Hank and Nick arrive at the hotel, Wu confirms Alex's name from the room register. The dead man had a Moscow driver's license, and Ivan's waiter uniform. They also find a discarded burner cell phone and try to call the last number, only to discover that it has been disconnected. As they talk, they realize that Alex isn't dead. He grabs Hank and collapses, and the trio undergo contamination due to possible radiation exposure.
As the three men take decontamination showers, they discuss the case and figure that Alex was exposed to the radiation at Dmitri's restaurant. A hazmat team go there to check while the men finish their decontamination. As they emerge from the showers and put on jumpsuits, the hazmat team call to tell them that the storeroom where Boris attacked Alex was radioactive. At the station, Hank and Nick tell Renard what happened. He tells them about Boris' previous profession as an assassin and tell the detectives to bring Boris in and see what he'll admit to.
As the hospital, a woman visits Alex and he tells her that she must leave the country before Boris kills her.
Juliette is working at the office and has brought Alicia along to keep her company. They talk about Joe and Alicia clearly still has feelings for him. Juliette warns her that she can never go back to Joe and Alicia reluctantly agrees.
At the station, Nick, Hank, and Renard question Boris and tells him that they know he's a Wesen. He realizes that Nick is a Grimm and admits that he was an assassin, but insists that he's given up that life and now tries to make up for the people he's killed by healing. The Koschei tells them that he has no idea who Alex is, and that he is killing himself every time that he heals someone. He figures that he will let the killers finish him off the next time they come for him because he's doomed anyway. Renard tells him to head back to Russia and Boris agrees, saying that his wife wants to go home. As he leaves, the hospital calls Hank to inform him that Alex has woken up and that he will soon die.
At Mila's home, someone pours poison into a bottle of vodka.
At the hospital, Alex tells Renard that Boris killed his father and is going to kill his female accomplice as well. However, he passes out before he can give them her name. They figure that it's someone in Mila's house and head there.
At the house, Boris and Olga discuss going back to Russia. Larissa comes in and Boris starts flirting with her again, grabbing a bottle of vodka. Disgusted, Olga leaves and Boris and Larissa go upstairs to one of the bedrooms. Boris glances back at Olga, who is watching the entire thing, but then goes on with Larissa. Furious, Olga loses control and transforms into her Malin Fatal form.
In the bedroom, Boris collapses on the bed, drunk and fatigued from the use of his powers. Larissa insists that he continues drinking but finally wonders why he isn't dying. When Boris wonders who she is, Larissa explains that he killed her father Sergei when she was 10, and he killed her brother Alex as well. Boris insists that he isn't the same man that he was then and begs her forgiveness, but she grabs a pair of scissors from a dresser.
Nick and the others arrive at the home and Olga greets them at the door. As she tells them that her husband is with Larissa, Boris staggers out of the bedroom, the scissors in his chest. Larissa runs down the stairs while the detectives draw their guns and tell Boris to stand down. Realizing what the maid has done, Olga transforms into a Malin Fatal and rips out Larissa's throat. Dying, Boris goes to Larissa and uses the last of his lifeforce to heal her despite Olga's protests.
When Nick returns home, Juliette and Alicia tell him about their day. As Alicia apologizes for imposing on them, the phone rings. It's Joe, who demands to know if Alicia is there. Juliette tells him that she isn't and Nick takes the phone, telling the man to calm down. He asks Joe why Alicia left him and the man hangs up. A sobbing Alicia warns them that Joe will come for him and that he isn't normal.
Outside, Joe puts away his cell phone and glares angrily at the house, briefly transforming into a Klaustreich.