A member of the Enterprise landing party on Pyris VII in 2267, who beams up dead and delivers a warning in a voice that is not his own.
Crewman Jackson appears in the second-season episode Catspaw. He is on the surface of Pyris VII with Scott and Sulu when contact with them is lost. Jackson alone signals for beam-up.
He materialises on the transporter pad and pitches forward on to the floor. McCoy finds that he is dead, with no visible cause. Then a hollow voice speaks through the corpse's open mouth, telling Kirk that there is a curse on his ship and that he must leave or die.
The warning brings Kirk, Spock and McCoy down to look for the missing men, and so into the castle of Korob and Sylvia. Jackson was played by the stuntman Jimmy Jones.