Induced by Himmler to become the chief investigator of the occult for the Nazis, Rahn traveled throughout Europe searching to the Grail and other mysteries. 'Lucifer's Court' is the travel diary he kept while searching. It was during this time that Rahn grasped the positive role Lucifer plays in these forbidden religions as the bearer of true illumination, similar to Apollo and the other sun gods in pagan worship. This journey was also one of self-discovery for Rahn. He found such a faithful echo of his own innermost beliefs in the lives of the heretics of the past that he eventually called himself a Cathar and nurtured ambitions of restoring that faith, which had been cruelly destroyed in the fires of the Inquisition. His journeys on assignment for the Reich - including researching an alleged entrance to Hollow Earth in Iceland and searching for the true mission of Lucifer in the caves of southern France that served as refuge for the Cathars during the Inquisition - also led to his disenchantment with his employers and his mysterious death in the mountains after his break with the Nazis.