Mister Sir began life as MR-SUR, or medical robot, surgery. Its mission was to preserve human life through application of its medical knowledge and skills. This directive made MR-SUR's experience during the great dieoff particularly painful. Despite its best efforts, the medical robot could not save humanity. It has few memories of the following years. These days, Mister Sir suspects it wiped that period from its memory due to trauma. When feeling maudlin, it acknowledges that it probably spent fruitless years operating on corpses.
Once it recovered somewhat, it found a new purpose: to renew the extinct human race. It hunted down scientific tomes on human reproduction, cloning, genetics. It recovered a large collection of related technology and made some new strides of its own — all theoretical, lacking subjects for its experiments.
When the Hirr occupied the formerly-human planet, Mister Sir knew its time was up. It concealed its trove of human technology and accepted the offer of safe deportation. It now works as a surgeon and general physician on StarHub. Mister Sir insists it hasn't given up on its dream of resurrecting humanity, and it asks all its patience for clues that may help with its lofty goal.