he crew of the Enterprise arrive at the planet EXO-III with some trepidation and great anticipation. They are there to see if hey can locate the renowned scientist Dr. Roger Korby. The man hasn’t been heard of for 5 years and the general belief is that he is dead. For Nurse Christine Chapel however, a reunion with Corby will be a reunion with her fiancé. They find Korby alive but when Kirk and Chapel beam down to the planet, they find a man obsessed who is using alien technology to reproduce the humans around him in the form of androids.