American author and screenwriter (1926–2013), known for I Am Legend and The Twilight Zone, who wrote The Enemy Within, in which a transporter accident splits Kirk in two.
Richard Matheson was an American novelist and screenwriter, born in 1926. His books include I Am Legend and The Shrinking Man, and he wrote many episodes of The Twilight Zone, among them Nightmare at 20,000 Feet.
His single Star Trek script is The Enemy Within, broadcast in October 1966. A transporter malfunction divides Captain Kirk into two men, one gentle and indecisive, the other violent and impulsive, and the story argues that a commander needs both halves to function.
The episode gave William Shatner an early showcase and also saw the first use of the Vulcan nerve pinch, devised on set by Leonard Nimoy. Matheson died in 2013.