The Ruin Haunters are one of the first posthuman species in the fiction work All Tomorrows to recover their sentience. During the reign of the Qu, the Ruin Haunters were one of the few posthumans that had not been genetically modified too extraordinary, so that after the Qu abandoned the Orion Arm they rapidly regained a technological civilization.
The Ruin Haunters' rapid rise and return to intelligence had some major drawbacks: their technological progress outraced their philosophical and social knowledge, leading to numerous global wars (with at least two involving nuclear exchanges). It also created a dangerous mindset that they had a "manifest destiny" of returning humanity to its original prominence, even at the expense of their other "human" cousins.
The Ruin Haunters eventually evolved into the Gravitals...a race of powerful sentient machines.