Zerbrechliche Klauen is a map set for registered Wolfenstein, made by Ryan Rouse. It was released on February 27, 2013.
The map set features 3 new levels on Episode 1. Rouse listed Thomas Weiling's 10 New Ones (for which he also did a review) as being an inspiration. Rouse has also made sets for Quake and Doom, with Zerbrechliche Klauen being his only contribution to Wolfenstein 3D modding.
The maps are in the classic vein with nice attention to detail and aesthetics.