Operation: Zeitgeist is a mod for registered Wolfenstein, made by Steven Trinkl. It was released on February 19, 2004.
The mod features 20 levels, found in the first two episodes. Originally made using Creator maps as a base, the final new demo version had only two Creator levels left with the rest being originals.
Sprites and textures are a mixture of original work and the then-in vogue ROTT guards from the Image World. Coding changes include textured floors and ceilings and a new enemy.
The storyline is in the futuristic/sci-fi vein, taking place in the United States in the year 2103.
A full version was never released.