Photos: Halloween Horror Nights at Universal Studios Hollywood

An actor catches guests off-guard in the scare zone at Halloween Horror Nights.

John Murdy, creative director of Universal Studios Hollywood and executive producer of Halloween Horror Nights, at the Psycho House at Universal Studios Hollywood.

An actor brings his character to life in “Eli Roth Presents the Terror Tram.” Roth, the producer of such horror films as “Hostel,” “Cabin Fever” and “The Stranger,” has been recruited to remake the park’s iconic tram ride by populating it with maniacal, serial killer clowns.

Actors scare guests near a wrecked airliner in “Eli Roth Presents the Terror Tram.”

Actors scare guests near a wrecked airliner in “Eli Roth Presents the Terror Tram.”

A scene from “Eli Roth Presents the Terror Tram” at the annual Halloween Horror Nights employee run-through at Universal Studios Hollywood.

A scene from “Eli Roth Presents the Terror Tram” at the annual Halloween Horror Nights employee run-through.

A scene from “Eli Roth Presents the Terror Tram” at the annual Halloween Horror Nights employee run-through.

Actors with chain saws greet guests during Halloween Horror Nights at Universal Studios Hollywood.

An actor scares a woman at the annual Halloween Horror Nights employee run-through.  (Allen J. Schaben / Los Angeles Times)

An actor scares guests at the annual Halloween Horror Nights employee run-through.

Actors scare guests at the annual Halloween Horror Nights employee run-through.

Actors with chain saws scare guests at the annual Halloween Horror Nights employee run-through.

An actor appears in a maze in which three chapters of “American Horror Story” come to life. The maze was designed by the TV series’ creator, Ryan Murphy.

An actor catches guests off-guard in a maze in which three chapters of “American Horror Story” come to life.

An actor appears in a maze in which three chapters of “American Horror Story” come to life.

Three chapters of “American Horror Story” come to life in a maze designed by series creator Ryan Murphy.

A clown stands at the entrance to “Eli Roth Presents the Terror Tram” at Universal Studios Hollywood.

An actor appears in a maze in which three chapters of “American Horror Story” come to life.

Actors appear in a maze in which three chapters of “American Horror Story” come to life.

An actor catches guests off-guard in a maze in which three chapters of “American Horror Story” come to life.

Guests react to an actor in a maze in which three chapters of “American Horror Story” come to life.

Three chapters of “American Horror Story” come to life in a frightening maze that takes guests through Ryan Murphy’s horror anthology to encounter scenes and characters designed to jolt them to the core.

An actor appears in a maze in which three chapters of “American Horror Story” come to life.

An actor catches guests off-guard in a maze in which three chapters of “American Horror Story” come to life.

An actor appears in a maze in which three chapters of “American Horror Story” come to life.

An actor appears in a maze in which three chapters of “American Horror Story” come to life.