Amsterdam Zoo Artis animal handlers supervisor Willem Kraan is found locked in the lion cage and practically devoured. His wife Marjan accuses his ex and alleged lover Ina de Vrede, with whom she had a crazy feud. Frank de Moor, whom Willem fired recently, was seen around. An animal smuggling opponent thinks the illegal trade gang they were after ordered him murdered, so De Cock searches for a possible inside accomplice.
A successful businessman is found murdered aboard a replica of a Dutch East India Company vessel. De Cock and his team find plenty of motives, for instance an ex-employee who went bankrupt because of him, and even the man's own children.
Leading Amsterdam restaurant critic Johannes de Boer is found in a street dumpster, poisoned in a triple mustard sauce dinner. His wife lies as if she were filing for divorce, while he was and the prenuptial would have left her destitute. His often abusive reviews ruined several restaurateurs, unlike his nephew Wouter Bossong, whose is still in financial trouble. Buitendam enjoys finding out which restaurant serves the mustard dish. De Cock however also discovers another type of grudge.
De Cock and his team investigate the murder on a generous woman who offered help to people in need of it. There is a key witness, but he has Down Syndrome, which De Cock knows will render his testimony useless in court.
De Cock and his team are in for a mysterious case when an unknown man is found dead in a car graveyard. The murderer appears to be a pro, but De Cock begins to doubt that theory after a second corpse is found.
De Cock and his team investigate the murder on a red-haired woman, and discover that there is a serial killer at work. Buitendam decides to call in an expert from outside the team, which only makes tensions rise even higher.
Lucrative Amsterdam dating service manager Caroline Hulst is found in her garage, a poorly staged monoxide-suicide. Suspects are her ruthlessly greedy partner Gerda Sieben, ex Marcel de Haan who has custody of their pre-teen daughter and two men who reacted to her contact ad: restraining order-slapped 'stalker' Jacco de Ridder and businessman Willem Groen. All lied about motives and/or alibis.