Infiltrating Hell

Operation Chaos, XXIII.

In Robert Heinlein's Magic, Inc, when the narrator and his friends are fighting demons in Hell, one demon suddenly changes sides and helps them to win. Later, he introduces himself:

"'Let me introduce myself,' he said in English. 'I'm Federal Agent William Kane, Bureau of Investigation.'"
-Robert Heinlein, Magic, Inc IN Heinlein, Waldo and Magic, Inc (London, 1975), 110-204 AT p. 201.

So the FBI has infiltrated Hell. Poul Anderson's Operation Chaos is what I call a conceptual sequel: same concept; different story-line. His Hell is not so habitable:

"'The Army's made several attempts to probe [the hell universe], with no better success than the Faustus Institute had thirty years ago. Men returned in states of acute psychic shock, after mere minutes there, unable to describe what had happened. Instruments recorded data that didn't make sense.' (p. 168)

One theory is that space-time there is non-Euclidean with geometry changing from place to place. This is similar to Magic, Inc. In the Half World, as Heinlein calls it:

custom, not natural law, persists;
up and down are matters of opinion;
directions might be in days or colors instead of miles;
there are a formless greyness and ever-changing mazes;
the ground twitches and pulsates.

However, the explorers experience all this without going into shock.