Voir The Outer Limits: The Complete Original Series - Episode 44

Scientist Eric Plummer comes under the sinister influence of a creature from outer space. It's capable of materializing in human form but lacks normal emotions. Plummer agrees to exchange his emotions for scientific data known only to the creature. The monster takes command of the scientist's emotions but has great difficulty in understanding such things as love and beauty which are unknown in his totally physical world. With the data Plummer harnesses a fantastic energy source and fashions a weapon capable of destroying all life. The creature begins to feel compassion for humanity and returns the scientist's emotions to him...and is now vulnerable to attack by those of his own weird world who resent his defection.