Stardate 3287.2: The Enterprise witnesses a smaller ship diving into the sun of Deneva under the control of a pilot who seems to have intentionally killed himself. This confirms Kirk’s worst fears, that a seemingly contagious outbreak of insanity on several other worlds has spread to Deneva, where his brother lives. On the surface, many are found to be dead – including Kirk’s brother – and an unknown species of alien parasite is found to be responsible. In trying to gather data on them, Spock is attacked and taken over by one, and, like the people of Deneva and several other planets, starts to go mad. Spock’s condition also presents McCoy with the first opportunity to learn more about both the creature and its victim, and Spock may have to die if the crew is to learn any more about the creatures to prevent them from spreading further into human territory.
written by Steven W. Carabatsos
directed by Herschel Daugherty
music by Alexander Courage
Guest Cast: DeForest Kelley (Dr. Leonard McCoy), James Doohan (Mr. Scott), George Takei (Lt. Sulu), Nichelle Nichols (Lt. Uhura), Joan Swift (Aurelan), Maurishka (Yeoman Zahra), Majel Barrett (Christine Chapel), Craig Hundley (Peter), Fred Carson (First Devenvan), Jerry Catron (Second Denevan)
Notes: Craig Hundley appeared again in Star Trek’s third season before embarking on a career as a musician; he would go on to create (and play) an unusual instrument called the Blaster Beam, whose distinctive sound was used heavily in the first two Star Trek films.
LogBook entry by Earl Green