In 2266, Darnell accompanied Captain James T. Kirk and Dr. Leonard McCoy to the surface of M-113, to perform a medical examination of Professor Robert Crater and his wife Nancy. Upon seeing Nancy (actually an image projected by the M-113 creature), she reminded him of a woman he once met on Wrigley's Pleasure Planet. He later became the first victim of the creature when he followed her out into the wilderness of M-113. While Nancy insisted that he consumed a fruit from a Borgia plant, a later autopsy by Dr. McCoy revealed that his body had been drained of salt. (TOS episode: "The Man Trap")