The earliest appearance of Spock in the series as broadcast was "The Man Trap", the first such episode. When he needs to knock out an evil version of Kirk in "", he uses a Vulcan nerve pinch. Spock and Chief Engineer Montgomery "Scotty" Scott (James Doohan) work together to rejoin the good and evil versions of the Captain, which had been split following a transporter accident. During "", he finds himself to be the only member of the landing party to be immune to the physical effects of the disease affecting human adults on the planet. However, he realises that he is probably a carrier and could infect the "Enterprise" if he were to return. Doctor Leonard McCoy (DeForest Kelley) manages to devise a cure, allowing the team to return to the ship.