A young girl washes ashore near Tricity, naked and with her lips grotesquely torn away. This tragic figure is soon identified as Monika Bogucka, the daughter of Helena Bogucka, a distinguished judge. The case soon falls into the hands of Leopold Bilski, a young local public prosecutor eager to uncover the heinous truth behind her murder. The investigation takes a chilling turn when the coroner notes striking similarities between Monika's murder and a case from over fifteen years ago, involving a man named Jakubiak, who had just been released from prison one week prior.
Jakubiak is quickly apprehended after police discover a bloodied shirt buried in his backyard; however, the situation escalates dramatically when he commits suicide during interrogation by Bilski, throwing the investigation into chaos. While Bilski's superiors are satisfied with the closure of the case, he remains unconvinced and feels compelled to dig deeper, unveiling a web of deceit and corruption.
Only months before her tragic demise, Monika found herself at "Dockyard," a notorious disco owned by Kazar, a local mafia kingpin. Taking a job there seemed innocuous, yet it drew her into the dark underbelly of the drug trade. Her fortuitous entanglement with Kazar soon morphed into a nightmare as he revealed himself to be not just a vicious murderer, but also a rapist. Monika’s attempts to alert the authorities to the criminal activities she witnessed fell flat when she discovered that one of the officers she confided in was a corrupt cop on Kazar’s payroll, effectively sealing her fate.
Meanwhile, Helena Bogucka suspects her husband may be hiding critical information. Her suspicions lead her to clandestinely follow him, uncovering his secret life as Kazar’s attorney. In a desperate quest to learn the truth about Monika, she visits the Dockyard, only to have someone drug her drink. Fortunately, she receives unexpected help from a sympathetic worker who, while connected to Kazar, aids her escape.
As Bilski continues his diligent investigation, he connects with Tadeusz Dubiela, the coroner who had previously examined the early murder case linked to Jakubiak and is also romantically involved with Helena. Tadeusz's son, Mario, was friends with Monika, adding an emotional layer to Bilski’s pursuit. He discerns a disturbing pattern, discovering that several women associated with the Dockyard have gone missing under eerily similar circumstances. His investigation leads him to uncover another of Kazar’s associates, who had a prior relationship with Monika, but when police backup arrives, the corrupt officer swiftly eliminates the potential witness.
In a desperate bid to expose Kazar's nefarious dealings, Helena’s husband entrusts her with a pendrive containing vital evidence of Kazar’s illegal operations. Although it risks his career, he is determined to bring Kazar to justice. Helena promptly relays this information to Bilski, who organizes a daring police sting operation aiming to apprehend Kazar. Although the sting uncovers several alarming pieces of evidence, it fails to reveal any tangible signs of the missing women.
As the investigation unfolds, they face further complications when a corrupt officer attempts to transport Kazar to prison, which Bilski counteracts by assigning the mission to another cop. Eventually, the truth about the dirty cop comes to light, leading to his downfall.
Despite the efforts of the scientific police, no concrete evidence of murder is found in Kazar’s home. However, a breakthrough emerges when Bilski discovers a gruesome bracelet made of human lips—trophies taken from Kazar’s victims. Kazar brazenly admits to the murders but vehemently denies any involvement with Monika's tragic fate.
As Bilski pursues this dark case to its heartbreaking conclusion, he and Helena take time away for personal reflection; Bilski heads to Warsaw to reunite with his daughter and ex-wife, while Helena plans a weekend retreat with Tadeusz. In a shocking twist, they discover Mario in an unexpected location, reigniting the investigation’s darkness when Bilski recalls seeing him hide a ruby ring that belonged to Monika.
A harrowing turn of events follows when Tadeusz knocks Helena unconscious, revealing that Mario had initially brought Monika to their retreat, where a tragic accident culminated in her death during a coercive encounter. Fearing prosecution, Tadeusz opts to frame Jakubiak to protect his son. Just as Bilski arrives on the scene, Tadeusz takes a drastic step, committing suicide in a moment of despair. The narrative culminates in Mario ultimately choosing to surrender to the authorities, bringing a chilling resolution to this intricate tale steeped in trauma, betrayal, and the quest for justice.
