resurrection is a major theme in mythology and also in fiction although, in realistic fiction, the character only appears to have been dead. Classic examples are Sherlock Holmes and James Bond. Stieg Larsson's Lisbeth Salander even survives being shot in the head and buried.
I mention this theme here because I did not think that it is prominent in Poul Anderson's works? However, I have not read Anderson's entire canon and am always interested in what blog readers might be able to contribute. The Time Patrol is discussed in the article linked above.