As a dedicated student of the sciences, Perrin Rhinehart earned their Intergalactic Language Doctorate from Cosmos Cantwell Medical College of Indus in order to better serve the needs of their people as they travelled the cosmos. Having lived life among the Pioneer caste, Perrin had helped to settle many new colonies in the galactic frontier, but decided to find a new purpose helping others with the Doctors. Now, with the native primates still in captivity on Earth, Perrin and the Doctors venture to fulfill the promise of release that the Homo Insipiens have reneged.