Agrajag is a piteous creature that is continually reincarnated and subsequently killed, each time unknowingly, by Arthur Dent.

Eventually, Agrajag becomes aware of his many past incarnations and wishes to take revenge on Arthur Dent, diverting his teleportation to a Cathedral of Hate. However, in the process of explaining his reasons for hating Arthur he mentions "Stavromula Beta," where Arthur ducks to avoid a shot fired by an assassin, which then hits Agrajag instead. Arthur, never having been to Stavromula Beta, has no idea what Agrajag is talking about, and Agrajag realises that he's brought Arthur to the Cathedral too early. Thus, any attempt by Agrajag to kill Arthur would be logically impossible. He tries to kill Arthur anyway, and once again dies at Arthur's hands while Arthur is defending himself, but not before setting off the explosives intended to kill Arthur by triggering a massive rockfall. Due to the laws of cause and effect and the laws of time and the universe (not to mention dramatic necessity), Arthur escapes the rockfall unharmed.

For the next few years Arthur travels the universe, secure in his knowledge that, no matter what happens, he cannot die at least until after he survives his assassination attempt at Stavromula Beta. In the novel Mostly Harmless Arthur's daughter Random Frequent Flyer Dent holds him hostage in a London club. When she fires her weapon Arthur dodges, causing the bolt to pass over his head and hit the man standing behind him. Earlier the victim (Agrajag) had dropped a book of matches which revealed the owner of the nightclub to be Stavro Mueller, and the name of the club to be Beta. Thus, what Arthur believed to be the name of a planet was actually the name of the nightclub, and Agrajag has died once again. Because of this, Arthur is now able to die as well, which, thanks to the Vogons, he does a few seconds later.