The very alien Xorn, who communicate by whistling and magnetic fluxes, did their best to defeat their own creation -- the Singularity. After the fighting in one of their city-ships had decimated both sides, the Xorn finally put themselves and their enemies into stasis.
Approximately 650,900,000 years later, they were awakened by primitives. And so was the Singularity. Capturing the primitives who could stand up to the Singularity longer, the Xorn made the interlopers fight for them.
Yet the fight still slipped out of their control. The awakened Xorn, alone in a galaxy that didn't remember them, decided to end it. They would take their city-ship, the Xorn, and the Singularity with them.
One group of primitives had shown respect, and they were granted access to the city-ship and one lone ambassador form an age long past.