Kenny is a bonafide computer whiz and gamer, low on social skills but brilliant at what he does. He’d be at the top of his game if it weren’t for his impossible eccentricities. Desperate for the attention of the opposite sex but existing mainly online, he rarely gets a chance to socialize. The thought of actually dating a real woman is terrifying, better to get the take-out and live with his mom. Then he meets Elena, falls in love instantly and completely freaks out. He is also the son of Carolyn Martens. Kenny observes firsthand his mother’s shady operations, and he watches his boss and colleague, Eve, head into dangerous territory.
Carolyn takes Eve to a decrepit building where a dingy office has been set up with all of Eve's information on the female assassin. Carolyn has set up an "unofficial-official" investigation that she wants Eve to run secretly. Kenny enters and is introduced to Eve as the person who has been gathering the evidence. Eve is allowed two more people for her team.
Eve invites Bill and Elena to come work with her. She brings them up to speed on the assassinations she believe were done by the same woman. Bill plays contrarian, asking for proof that it is the same person for all the killings and proof that it is a woman. Eve excuses herself to the bathroom and is reminded of the encounter with a nurse in the hospital bathroom before Kasia was killed. When she returns to the office, she asks Kenny to look up any females worldwide aged 16-45 who have medical or prison records displaying psychopathic traits.
When Eve and Bill arrive at the office, Carolyn is waiting with Elena and Kenny to let them know that there has been another assassination. Eve thinks that Carolyn is referring to Carla de Mann but Kenny tells her that it was a Chinese colonel, Zhang Wu, who has been killed. The name the assassin gave to the receptionist was "Eve Polastri".
In Berlin, Eve asks Bill to watch their suitcases while she calls Kenny to see if he can locate Jin's whereabouts from his email address. Kenny sends her Jin's location as she notices that her suitcase has gone missing.
Eve meets with Elena and Kenny to discuss the suitcase and perfume. She assigns them the task of finding out where the clothes were bought and if there is any DNA or security footage. They head to the office as Eve continues providing instructions but stops when she sees Bill's empty desk. Kenny has gone through the documents Jin Yeong gave Eve at their dinner in Berlin and there are bank statements from the Cayman Islands used to pay off the Chinese double agents that Zhang Wu uncovered. Kenny has noticed a British account number receiving three payments a year of $17,700 that terminates at St. Henry's prep school in Sussex.
Eve remembers a work party a year ago where Frank got really drunk and emotional about not being able to afford to send his kids to St. Henry's school. Kenny starts tracking Frank down so they can bring him in for information and finds him in a village called Bletcham in Buckinghamshire.
Kenny calls Eve and Elena as they are on their way to Bletcham to let them know that someone called Frank's phone from a landline at the same place his phone is at. As they arrive in Bletcham, Kenny relays to them that Frank is speeding away.
After rescuing Frank from the assassins, Elena and Eve question him. Frank remembers that one of the girls was named Oksana. Eve contacts Kenny and asks him to look up the name Oksana. He tells Eve that the DNA results on her suitcase came back and Villanelle's DNA is all over it.
Later, Eve calls Kenny to inform him about the Twelve. She also encourages him to give Elena a call. Back inside the safe house, Carolyn tells Eve that the police have found Diego's body but no one else. Carolyn asks after Kenny since Bill's death because Kenny's own father died a few years ago. Eve promises to keep an eye on him.
When Eve arrives at the office, it is empty. She picks up a baby blanket off Bill's desk when Kenny returns. He tells her she should still talk to Bill even though he is gone because it helps. Kenny has found prison records on a few people named Oksana and Eve stops when she sees the picture for Oksana Astonkova. Kenny tells her that she supposedly died in prison four years ago. She was imprisoned because she "chopped [a man's] knob off."
After Villanelle visits Eve at her house, Eve rushes over to Carolyn's house, interrupting her at dinner with friends and Kenny, who is her son. Carolyn takes her and Kenny into another room and Eve explains that Villanelle has her phone, which gives her access to Frank's interview and his location. She also asks for protection for Niko.
In Eve's office, Kenny reports that Nadia was picked up in Bletcham by Russian intelligence and was taken to the same prison Villanelle "died" in three years previously. Eve asks Carolyn if they can go to Moscow to question Nadia. Both Kenny and Elena opt out of the trip.
In Russia, Eve calls Kenny to see what he found out about Anna. Kenny tells her that Anna was the wife of the man Villanelle had castrated six years previously. Eve asks Kenny to dig up any information on Konstantin and Carolyn. Kenny calls Eve back that he found letters from Konstantin.
As Eve and Carolyn walk the streets of Moscow, Carolyn reveals that Kenny is now in Moscow. They arrive at a shop and are allowed into a backroom where Kenny has set up a temporary office.
At their new office, Eve tries to get the heat to work as she hypothesizes that "Natalie" is actually Villanelle. Kenny volunteers to check CCTV for visitors but Carolyn shuts him down. Eve changes tactics and decides they must find Anna. Carolyn says it is unnecessary and asks Kenny to have Elena fly them back to London since there is nothing left for them in Moscow. Carolyn will remain behind to "tie up" some things. After Carolyn leaves, Eve and Kenny decide to remain in Moscow anyway and Kenny presents Eve with some personal letters of his mother's that he found.
The letters Kenny found are dated from 1977-1978 and are of an explicit nature. Eve is planning to give them to Vlad as proof that he was not the one involved in the plutonium plot but asks Kenny to go through them to see if there might be a code. Kenny also found some old photos, one of which has Konstantin sitting with Carolyn. He provides Anna's address to Eve and she tells him it is okay if he wants to go back to London. He wants to stay and is planning on going through the CCTV cameras at the prison to look for Villanelle.
Eve enters their temporary office and joins Kenny to search through the CCTV footage. She speculates on Anna's and Oksana's relationship. Eve spots a prisoner from behind that walks like Villanelle. Kenny finds another angle and they zoom in on Villanelle's face, confirming that Villanelle was in the prison with Nadia. On the CCTV, Villanelle is led into a visitor's room where Carolyn shows up to meet with her.
Eve and Kenny walk through the streets of Moscow. Eve wants to confront Carolyn about meeting with Villanelle in prison but Kenny is scared of Carolyn. They arrive at Carolyn's hotel and Eve convinces the front desk to give her a key to Carolyn's room. Kenny wants to knock first to make sure Carolyn is not in the room. They find Carolyn's room a mess and Konstantin standing with a hair dryer. Carolyn exits from the bathroom and stops short when she sees Eve and Kenny. Eve states that Villanelle is in the prison. Carolyn explains that she escaped, locked Konstantin's wife in a cupboard, and kidnapped his daughter.
At breakfast, Carolyn tries to send Kenny away but he asks why Konstantin's security isn't looking for Villanelle and Irina. Konstantin reveals that the Twelve want him dead. Eve thinks they should go back to Anna's and calls her. Carolyn sends Kenny to pack up their equipment, threatening to fire him if he refuses, while she is going to visit Vlad to set up protection for Anna.
Kenny begins packing away their equipment when something on the prison CCTV catches his eye. He witnesses a guard picking up the piece of paper Nadia slipped under her door before Villanelle killed her.
At the airport, Carolyn informs Eve and Kenny that Konstantin has died. Eve checks her voicemail and hears a message from Elena that a young man (Sebastian) was found dead at an apartment in Paris with the same chemical in his system that killed Carla de Mann. Elena uncovered that one of the apartments is paid for by the same account that was paying off Frank. Eve lies to Carolyn and tells her it was Niko on the phone. Carolyn confronts them about giving Vlad her love letters to Konstantin and fires them both. Carolyn and Kenny board the flight to London but Eve takes off in another direction.