A 2007 film by Tom Shankland. In a permanently raining American city, a sour, embittered police officer, Eddie Argo (Stellan Skarsgård) is paired up with a new partner, the pregnant and idealistic Helen Westcott (Melissa George). They investigate when a string of bodies are found, all bearing the W delta Z formula (which gives the movie its international name), and gradually unravels the mystery, linked to a violent gang (Tom Hardy, Sally Hawkins, and Ashley Walters) and a traumatized woman, Jean Lerner (Selma Blair).
This film contains examples of:
- Brooding Boy, Gentle Girl: A particularly dark and non-romantic version. The kind, idealistic, and pregnant Helen is the new partner of the miserable aggressive Corrupt Cop Eddie.
- Carved Mark: The killer carves the mathematical formula "W Delta Z" into their victims' bodies.
- Closet Gay: Eddie has been having a sexual relationship with Daniel.
- Dating Catwoman: A gay male version. Eddie is sleeping with gang member Daniel.
- Depraved Homosexual: Played with. Daniel, who Eddie was sleeping with, is a gang member who viciously raped, tortured, and murdered Jean's mother, and raped and tortured Jean. Eddie is also a majorly Corrupt Cop, but he genuinely loves Daniel and actually sacrifices his life for him.
- Even Evil Has Loved Ones: Invoked, and deconstructed. Jean targets the gang members by kidnapping their loved ones and giving them the option of being brutally tortured or their loved ones being killed. None of them manage to pass her test...until Eddie does at the very end.
- Gayngster: Daniel, since we only see him having sex with Eddie.
- Gray Rain of Depression: The story of sexual assault, brutal murder, and corrupt police is set against a permanent grey rain.
- Imperiled in Pregnancy: The film begins with the discovery of a dead pregnant woman with the "W Delta Z" formula carved into her belly.
- Paper-Thin Disguise: When the police get video of the unmarked white van that Jean is using, she camouflages it with spray paint to make it look like a conversion van. At night and from a distance, the disguise works well enough, but would be noticeable up close or during the day.
- Villainous Parental Instinct: Subverted. Jean, who is still mourning her mother, believes that her equation (that love can be stronger than pain), although it's failed so far, will be proven when she kidnaps Elly and her young son. It fails nonetheless and Jean has a Villainous Breakdown.
