Another vague idea. A few hundred thousand years ago, a race of aliens exploded out into space. They built the first empire, dragging in other space-faring races and placing primitive worlds (like Earth) under quarantine (explaining why we didn’t get any mail from ET). Their empire grew very fast, but the population started to refuse demands for military service and so on. The Boss Race had built their empire on the labour of non-Bosses. This didn’t make them popular among their subject races – and as their technology spread, they discovered that they were facing an invasion from races that had absorbed their technology and had friends and allies among the subject races. Their technology was still primitive compared to the master race, but there was a heck of a lot more of the barbarians. After a version of the Battle of Adrianople that wreaked a large space fleet, the master race’s leaders knows that they are in trouble.
Their solution – hire humans to serve as soldiers, in exchange for the keys to the stars.
Unluckily for them, humanity doesn’t want to serve as slave-soldiers, holding down the oppressed masses…
Thoughts? Remember to read the ‘about me’ page before commenting.