Baptiste begins with a cold open in Deal, England, as a beachcombing pensioner arrives home. Apparently, no one told him when a man comes to read the gas meter tossume an assassin, Romanian, in this case, named Constantin (Alec Secăreanu). This killing is rough enough that there's a chainsaw involved. But no rougher than Julian Baptiste (Tchéky Karyo) is having it right now at home. The detective, who annoyed so many clients in The Missing, is now retired and forced to annoy his family, especially his daughter Sara (Camille Schotte) and her husband Ron (Omar Baroud).
Baptiste: I fought the same battle with my daughter. She thought she was taking drugs, but really they were taking her, piece by piece. But for blind and foolish luck, it could be her in the life your niece found herself living.
Desperate to get Julian out of the house, his wife, Celia (Anastasia Hille), sends him off to meet with one of his old colleagues, Martha Horchner (Barbara Sarafian), to have coffee. Baptiste says he is happy to be retired now that the tumor is gone from his brain. But Martha's got a case. He attempts to protest, insisting he's slowed to much with age to find a missing girl, a teen sex worker named Natalie Rose (Anna Próchniak). But she won't take no for an answer. Edward Stratten (Tom Hollander) is making a fuss around the red light district looking for her.
Natalie is Stratten's niece. He's raised her since she was 14 when his brother and his wife died in a car crash. Stratten left behind his relationship with Clare (Clare Calbraith) in hopes of a fresh start in Antwerp. But Natalie got into drugs, and now Stratten visits every two months. This time when he arrived, her roommate said she'd disappeared. Stratten believes Natalie was taken by a Romanian gangster named Dragomir Zelincu, who Natalie said she knew.
Meanwhile, in a basement, Constantin is on the phone, while his underling, Nicolae (Zachary Baharov), takes payment from drug runners. The phone call is a report that the police have brought in Baptiste to consult on the Stratten case, and Constantin wants him checked out. Elsewhere, in a house above a coffee shop, Greg (Trystan Gravelle) is asking Kim (Talisa Garcia), to marry him. It's the fourth time, and she's as unimpressed as she was the first three. She'd rather enjoy breakfast without saying yes, thanks. But Kim's reasoning may be more than just a dislike of public displays of affection. Her vanity has a false back, and inside, there's HRT (hormone replacement therapy).
The next morning, Stratten takes Baptiste to meet Natalie's roommate, Lina (Martha Antonio). She seems to have no interest in helping. But after her shift, Lina goes straight to Kim's coffee shop. Lina believes she's next, and all the girls on the row are terrified. It explains why they refuse to talk to Stratten and why Baptiste is getting nowhere. Knowing that Constantin is already onto Baptiste is worrying, especially when Celia, grandbaby in tow, blithely walks right by him at the market. He deliberately bumps into her, somehow managing to get his hands on her purse for a minute, where he bugs it. But Celia's no fool. She may be flustered in the moment, but her look back says she's not going to forget his face.
Far away from the city, out on a tulip farm, the owner, Herman (Gijs de Lange), finds Natalie's necklace lying in the dirt.
Baptiste notices he and Stratten are being watched. Stratten's response is to run right at the kid, prompting a chase across the city. The kid turns out to work for Walter De Louw (Manou Kersting), of The DreamRoom. They take a visit and discover The DreamRoom is a brothel specializing in trans women. Due to the nature of the brothel, De Louw insists he has no dealings with Natalie Rose, but Baptiste citing Zelincu's name rouses him to throw them out.
Baptiste's questions get them noticed, as Kim calls them to chat. She runs a collective of sex workers and knew Natalie, a junkie who pissed off the wrong people. Kim says she got deep in debt to the Romanians, and one of the girls said Natalie was going to run to Germany. Notably, when Baptiste name-drops Zelincu, Kim doesn't flinch. Stratten swallows it hook, line, and sinker, despairing of finding her. If Kim planned to drive him out, it worked, as he's ready to give up and go home.
Meanwhile, somewhere, in a basement, kidnapped girls have been rounded up for sale. The girls watch in horror as a buyer chooses "Number 6" in the line-up, and the poor thing is dragged out. One sits in the corner, too sick to stand, coughing her lungs out. At the tulip farm, Herman's dog has dug up a body.
Baptiste is exhausted, but once home, Sara's DVD collection sparks a thought about what he saw in Kim's apartment. He calls up Martha for the files on Zelincu. The next morning, Baptiste returns to Kim's house. The DVD that sparked him was an old Rita Hayworth film, and all the DVDs at Kim's starred the legendary actress, whose poster was up on the wall at The DreamRoom. Though Kim passes like a champ, a sharp eye can see the resemblance to the CCTV footage of Dragomir Zelincu in the shape of her face. Many would come after her, should she ever surface. But she knows where Natalie is and tells Baptiste in return for him keeping her secret.
In the basement, one of the girls tries to talk to the sick one, who says her name is Cristina (Freya Kingsley). She was snatched months ago at a bar in Amersterdam while visiting her sister Natalie. Wait, what? Edward never said there was a sister. Meanwhile, Baptiste finds Natalie, right where Kim said she'd be. She's thin, but she doesn't look like a junkie. But upon being asked about Edward, she shakes her head. Stratten isn't her uncle. He's not who he says he is at all. As the episode ends, Stratten returns home to find a few flies. They're coming from the basement, where the trophy head of the man from Deal sits on a shelf.