The Brain of Socrates ( short story ) The Brain of Socrates was the second short story in the Short Trips anthology " " . It was written by Gareth Roberts . It featured the Fourth Doctor and Leela . Summary . Grimmon , a Jezark , has crash - landed on Earth . Though he survived , his craft is a wreck . As he surveys the area around him , he is approached by two natives . They react in fear at the sight of him and throw their spears at him . He is unharmed and shoots them with his blaster . He explores the nearby area and looks down on the city of Athens . The Doctor decides that Leela needs to learn about comedy . He takes her to ancient Greece , birthplace of comedy . She is dressed for the part , but the Doctor is not . As they walk the streets of Athens , however , strange looks are directed at Leela . She notices that there aren ' t very many women about . They head for the amphitheatre , where the Doctor promises they will see a comedy . They see a play written by Aristophanes , in which Socrates is mocked . Leela does not understand why the wise man is mocked . The Doctor tries to explain , but gives up and instead takes Leela to the home of Anaximander , who is hosting a gathering . The Doctor and Leela crash the party and are welcomed by Anaximander , who introduces his guests : Socrates , Aristophanes , Euripides and Plato . The Doctor introduces Leela as his wife from Sparta . As they discuss Aristophanes ' play , a strange " bird " is heard . Suddenly , Socrates ' face goes blank and he leaves . The Doctor ' s sub - plasmic beam detector ( the " bird " sound ) has alerted him to a signal that should not be on Earth at this time . He excuses himself , leaving Leela behind , but after listening to the men ' s conversation without understanding it , she follows the Doctor . The Doctor and Leela follow the signal , with the Doctor confiscating Leela ' s knife . They track the signal to where Socrates is standing by a wall . The wall starts to glow and Socrates walks through it . The Doctor realises that someone has used a de - atomic transformer on the wall , and he and Leela hurry through it . They continue to follow Socrates , who eventually arrives at Grimmon ' s crashed spaceship . Socrates starts working on the ship , but doesn ' t respond to the Doctor . Leela senses an attack and knocks the Doctor out of the way . Grimmon appears , and he and the Doctor discuss Grimmon ' s predicament . The Doctor is horrified that Grimmon is using Socrates ' brain to repair his ship , and even more horrified that on takeoff Grimmon ' s ship will destroy the surrounding area . Grimmon doesn ' t think it ' s important , as this planet is not significant . The Doctor suddenly agrees with Grimmon , but then grabs him and holds Leela ' s knife at his chest . Leela takes Socrates and heads for the TARDIS , where they will wait for the Doctor . The Doctor arrives at the TARDIS , and Socrates returns to his senses . The Doctor sends him on his way , and after he leaves , the Doctor and Leela see Grimmon ' s ship take off . Leela thought the Doctor had killed him , but instead he helped repair Grimmon ' s ship and sent him on his way . The Doctor and Leela leave Athens as well , with the Doctor lamenting that " every other person on the street ' s a vital historical figure . " On entering the TARDIS , the Doctor bangs his nose on the door ; Leela laughs .