 What ultimately brings Torp down?
His task now was to bring a native, intact if possible, back to the carefully buried space cruiser where his two fellows and himself would drain the creature's mentality of all its knowledge. Men had no mates on Ortha, sex had been overthrown with all the other primitive impulses of barbarism; so he was incapable of understanding the emotions that swept through his acquired memory. Tonight or tomorrow night at the latest he must contact his two fellows and report that Earth was a planetary paradise. An expeditionary force to wipe the grotesque civilizations of Earth out of existence would, of course, be necessary before the first units of new Hordes could be landed.
 Thip shoots him with a blaster before he can comprehend what happened.
 He went mad from the same disease that's afflicting Thip.  Thip shoots him with a blaster before he can comprehend what happened.  His own madness. His overly trained mind can't handle the new circumstances.  He was never trained for a situation like this. He's not able to keep up with Thip.