In *Birds of Prey (and the Fantabulous Emancipation of One Harley Quinn)*, the setting functions as a physical manifestation of Harley Quinn’s chaotic psyche. Director Cathy Yan and production designer K.K. Barrett utilized real-world Los Angeles locations and stylized sets to dictate the pacing, choreography, and tactical shifts in the action.
### 1. The "Booby Trap" Funhouse: Action as a "Carousel Clock"
The final battle takes place in a derelict amusement park funhouse called the "Booby Trap." Originally scripted to occur in a hotel, Yan changed the setting to a funhouse to better reflect "Harley’s mind on acid."
* **Rotational Choreography:** The fight features a large, rotating carousel. Because the background was constantly shifting, the crew used the carousel like a **clock**, numbering specific points on the set to ensure the actors’ movements synchronized with the camera’s position.
* **Verticality and Props:** The funhouse environment—filled with slides, spinning floors, and "bouncy props"—forced the action to move vertically and unpredictably. Characters use the environment's traps (like the giant hand or the trapdoors) defensively, turning a confined, hostile space into a tactical advantage for the outnumbered women.
### 2. GCPD Evidence Room: The "Cocaine Power-Up"
During Harley's break-in at the Gotham City Police Department, the setting of the evidence room directly alters the trajectory of her combat style.
* **Environmental Stimulants:** A pivotal moment occurs when mercenaries accidentally shoot a pallet of cocaine. Harley inhales the powder, which acts as a narrative and visual "power-up." This shifts her movement from calculated gymnastics to a high-speed, hyper-aggressive style reminiscent of a "boss fight" in a video game (specifically inspired by the *Injustice* series).
* **Improvisational Weaponry:** The tight aisles and shelving units of the evidence room force the action into a linear, "hallway fight" progression, where Harley uses an aluminum bat and the close-quarters layout to neutralize large groups of gunmen.
### 3. Hawthorne Plaza: The Roller-Derby Chase
The climax transitions from the funhouse to a high-speed chase through the Hawthorne Plaza (an abandoned shopping mall).
* **Derby Mechanics:** The setting allows Harley to utilize her roller-skating background. The action uses a "whip" maneuver—a real-world roller derby technique where a teammate (Huntress on a motorcycle) transfers momentum to a skater.
* **Urban Obstacles:** The multi-level structure of the plaza and the long, flat stretches of the surrounding streets dictate the "skitchy" nature of the chase, where Harley is towed by a motorcycle to bridge the gap between foot-based combat and vehicle-based pursuit.
### 4. Roman Sionis's Club and "Skid Row" Alleys
The urban grit of "East End" Gotham (filmed in LA’s Skid Row and Chinatown) dictates the "scrappy" nature of the early action.
* **The Rescue Sequence:** When Black Canary rescues a drunken Harley in an alleyway, the narrow, cluttered space necessitates a brutal, close-quarters style. The setting encourages the use of **environmental weapons**—such as car doors and trash—rather than traditional superhero gadgetry.
* **Psychology of Space:** Roman Sionis’s club is designed with a "bird’s eye view" from his loft, emphasizing his surveillance and control. The action typically begins with a descent from these heights, representing the characters breaking out of his "collection" and into the uncontrolled chaos of the streets.