The Enterprise is en route to visit Dr. Korby, a brilliant scientist working in isolation who also happens to be Nurse Chapel's fiance. Kirk and Chapel beam down and discover that Korby has used abandoned technology left behind by an extinct civilization to create android companions for himself - one of which, an attractive and very user-friendly 'girl', arouses Chapel's suspicions. Korby, however, has become deranged in his isolation, and wants to take over the Enterprise so he can populate the 'inferior organic universe with androids...
