All of our immortals in the Errthe Books come from the planet Schkrapmerche and are referred to as Schkrapmerchants. They are naturally immortal. Actually, that’s not quite true – they do eventually die but by then they’ve outlived numerous star systems.
At the beginning of the first Errthe Book – Errthe I – In the Beginning – (good appropriate title that) they are all political prisoners who have been sentenced to exile on a new planet they will be expected to colonise. Because they are political prisoners, rather than real criminals, and because the authorities don’t want any dissent or discord in their society, they are treated as pioneers and sent on their way with all the panoply of heroes going into battle.
However, they are not destined to travel very far because their spaceship has been sabotaged. And this is where the chaos begins. The saboteur is a bungling idiot who can’t get it right. He reprogrammes the astro-navigation computer with a recipe for hot buttered scones. The ship goes crazy and leaves the galaxy altogether, crossing the inter-galactic wastes and entering our Milky Way galaxy where it crash lands on the dark side of the Moon. They decide to rebuild the ship and fly across to a nearby blue planet in the hope of finding some khofi.
They build their base under the antarctic ice and several centuries pass during which they become increasingly bored. Then they find a race of semi-intelligent apes and this is where the troubles really being. They decide to speed up evolution with the intention of creating a new race they will become the gods to. God help us all.