Van der Valk's Season 2 finale begins straightforwardly. Cellist Fleur Mas (Hadewych van Gent) goes to work, performs at a concert, and has a "drink" thrown in her face during the reception, which turns out to be acid, falls screaming, and dies. The next morning, VDV is having a nice coffee with Lena, planning a day off in Paris. It could have been a beautiful day, but then his phone rang.
VDV: Considering you started "No to Silence," I thought you might like to talk.
Mas, 23, was a child prodigy; her farmer parents weren't around her much growing up. Just before the performance, her last call was from Amsterdam Tower, where CCTV shows her meeting with Arjan Hersi (Thomas Acda), a well-known investigative reporter and friend of VDV. Hersi initially lies about knowing Mas, but when VDV corners him, he says he is protecting his source. He looks alarmed when told she's dead and says VDV should be too. As soon as they leave, he messages Hester Gill (Sallie Harmsen).
Cloovers is late, waylaid by his estranged sister, Elisha (Shereen Cutkelvin). Upon arriving, he and De Vries head to the concert hall to question artistic director Christiaan Timmerman (Michiel Nooter) and conductor Femke de Haan (Eva Marie de Waal), the latter of whom is Haskel's ex-girlfriend from last season. Fleur is who she left Haskell for, and she angrily tells Cloovers the police never looked into Fleur's reports of a stalker. Haskell doesn't take her ex as being involved well, but she puts a brave face on it.
Cloovers can't find any reports of a stalker. But he finds Mas regularly performed for Stefan Bodecker (Adrian Schiller), an accused groomer of underage girls for the rich and famous. He's fled the country (natch), but the concert Mas was prepping for was for "No To Silence," a sexual assault charity founded by Hester. VDV calls to ask Hersi if Bodecker is involved, and gets hung up, meaning "Yes." However, when Cloovers and De Vries return to ask Femke about Bodecker, she says she knows nothing about this. She assumed the stalker was Timmerman, who's been crushing on Mas while sleeping with the second chair, Carol (Lidewij Mahler).
When Bodecker fled, he sold his club to Anouk Prinsens (Jeany Spark), his former second-in-command. She tells Haskell she was ignorant of Bodecker's trafficking girls and has not contacted him since buying the club, which she renamed Maya. Hersi meets with VDV, speaking only in code, referencing The Battle of Schooneveld's first and second battles before giving VDV a book on it, saying "Happy Birthday." VDV then checks on Hester, who is skittish, and refuses to talk to him. When he returns, Police Chief Ludlow from the season premiere is in. Cloovers turned up a superyacht Bodecker might be on, and Ludlow says he'll get Interpol on it. Cloovers also found two local associates, Ivo de Witt (Kay Greidanus) and Quinten Arkas (Daniël Kolf).
Arkas is a turncoat, smuggling girls like Ella out of Bodecker's reach while dodging De Witt. He won't go on record; however, he does give them De Witt's location, who VDV foolishly stalks and gets beat for his trouble. He does find De Witt has photos of Femke and Hester and decides to warn the former while asking Haskell to try with the latter. Cloovers gets a call from Elisha, who is using when he arrives. She defends her casino job as "stands behind a table," not one where she makes money under it (or other people). VDV tracks Cloovers and meets Elisha, putting together that Cloovers owns the apartment where she lives.
De Vries finds Anouk's been emailing Bodecker. Haskell heads to Maya to confront her and sees Hersi and Anouk arguing before he exits hastily. Anouk says Bodecker sold her the club in a way that retained a hold over it, necessitating contact. As VDV arrives at Maya, Hersi texts to meet, only to be stopped at gunpoint and beaten. VDV and Haskell pull up as Hersi's thrown from his window. They leave the scene to Davie and arrest Anouk, who then admits her emails were actually helping Hersi hack Bodecker's computer, to get the secret videos he took of his clients with the girls, which he kept as collatorial. Hersi was putting together an expose to take down not just Bodecker, but the powerful people who demanded the supply. Anouk was a victim, as were Fleur and Hester.
Hersi was trying to warn Anouk, and as Bodecker's prints are all over De Witt's house, it seems he is back in town orchestrating these murders. VDV says to send someone to Hester's but he's too late. Hester already ran from De Witt and calls Haskell begging for help. De Vries and Cloovers drive Anouk to the safe house, but Hester laughs when VDV suggests the same for her. She's not wrong, as Anouk is kidnapped right from the car. VDV realizes what he should have done when Cloovers first said the stalking wasn't in the system. The station has a mole.
Haskell visits Femke, giving her pepper spray. Femke admits Mas was super troubled, and it sparked her protective streak. Haskell asks if Mas had a journal that might confirm Hersi's research, but she doesn't know. As for VDV, his conversation with Lena sounds like he's going to break it off again, out of fear for her safety, but actually, he's asking to take it up a notch, commitment, exclusivity, the whole deal. Lena's response was no, she wants to keep it light because she's... getting married. VDV is stunned and after a moment, they agree she should maybe leave now.
With Lena now gone, VDV's boat becomes the new office away from the office, with Davie as head chef, Ludlow warns someone wants to shutter the investigation, so VDV asks Cloovers to decode "the Battle of Schooneveld" clue. Haskell gets word Timmerman was attacked, meaning Femke, who has found Mas' journal, is next. The pepper spray saves her life; she escapes long enough for VDV and Haskell to reach her and arrest De Witt.
The team now has the journal, and Arkas' Ella, another source for Hersi, revealing a second location where girls were groomed and an address. Before they go, de Vries finds that Bodecker's long-term late mistress was named Maya. Bodecker is at the second location, hanging out with his daughter: Anouk. She's been sabotaging the investigation from the beginning. Bodecker smooth-talks VDV and Dahlmer, knowing his video collateral protects him; Anouk refuses to break either, insisting her father's innocent. Bodecker then realizes VDV doesn't have Hersi's video evidence, or they wouldn't be playing this game, much to the detective's frustration.
VDV heads back to join Cloovers in beating their heads against the Battle of Schooenveld code. Both battles were in the year 1673, and Hersi wished VDV a Happy Birthday on April 9. VDV says Hersi knew that because they'd met at Central Station that day. De Vries realizes Central Station has a locker room, and lo: Locker 1673, code number 0904, has a laptop with all the evidence... including Ludlow, the station mole. Sadly Hester shoots Bodeker, who will never see justice. But powerful men are being arrested all over Amsterdam, and the girls they were grooming are freed as VDV sails into the sunset.