What was the name of the conspiracy, which Carl Wentzel-Teutschenthal participated in and got executed for?
Carl Wentzel:  He was executed at Plötzensee Prison in Berlin following the 20 July plot to assassinate Adolf Hitler. 20 July plot:  The name Operation Valkyrie, originally referring to part of the conspiracy, has become associated with the entire event.
Operation Valkyrie