The audience is intended to **root for** the protagonist, **Detective Eric Visser**, and emphatically **root against** the antagonist, **The Amsterdam Maniac** (the scuba-diving serial killer).
Here is a detailed breakdown of the characters and the actions that drive this audience perception:
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### **Character the Audience Roots For: Detective Eric Visser**
**Who He Is:** Eric Visser, played by Huub Stapel, is the film's determined, tough, and intuitive police detective who is tasked with solving the series of brutal murders in Amsterdam's canals.
**Why the Audience Roots for Him (His Actions):**
1. **Dedication to Justice:** Visser is introduced as the competent officer assigned to a gruesome and baffling case—a serial killer using the city's unique waterways as both a hiding place and a weapon. His singular focus on tracking the killer establishes him as the hero and the audience's surrogate in the investigation.
2. **Relatability as a Single Father:** The film adds an emotional dimension to his character by showing him as a single father raising his teenage daughter, Anneke. This personal responsibility makes him a more sympathetic and grounded hero, contrasting his dangerous professional life with his vulnerable home life.
3. **Heroic Action and Pursuit:** Visser’s most significant actions that solidify his heroic status are the spectacular action sequences, particularly the **high-speed boat chase** through the narrow canals. This extended, thrilling pursuit is a clear demonstration of his courage, skill, and unwavering commitment to catching the killer, regardless of the danger.
4. **Climactic Confrontation:** In the film’s finale, he confronts the killer, ultimately shooting him to save his love interest, Laura. This action fulfills the traditional hero's journey, concluding his pursuit and protecting the innocent.
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### **Character the Audience Roots Against: The Amsterdam Maniac**
**Who He Is:** The Maniac, portrayed primarily by Door van Boekel, is the anonymous, scuba-diving serial killer. He is later revealed to be an unnamed former sailor, a friend of Martin Ruysdael, who was disfigured and driven insane by exposure to toxic chemicals (uranium hexafluoride) during a hazardous diving operation.
**Why the Audience Roots Against Him (His Actions):**
1. **Brutal, Random Violence:** The killer's actions are indiscriminate and exceptionally violent, establishing him as a pure source of terror. His spree begins with the gruesome murder of a prostitute, whose body is later horrifically displayed to tourists on a canal boat. He continues to kill random victims—including environmentalists, a Salvation Army member, and a young woman on an inflatable sunbed—making his targets purely innocent, which maximizes the audience's desire for his capture.
2. **Theatrical Presentation of Death:** The killer's choice of methods—using a butcher knife and a harpoon gun, and dragging victims into the water before displaying them—marks him as a sadistic threat. The terrifying point-of-view shots from his perspective as he lurks in the murky water amplify the fear and his status as the villain.
3. **Attacking the Protagonist's Allies:** The audience's antagonism toward the killer is intensified when he successfully murders Visser's friend and river police partner, John van Meegeren. This action makes the conflict personal for the hero, further justifying the audience's wish for the killer's death.
4. **The Climax as a Final Threat:** In the film's climax, the killer attempts to murder Laura, Visser's new love interest, directly putting the hero's personal life in mortal jeopardy and necessitating Visser's final, satisfying act of killing the antagonist.