A dreaded disease, choriocytosis, strikes the U.S.S. Enterprise. All except Spock are cured, as the illness is fatal only to Vulcans. With the starship on course to a Starfleet Academy dedication ceremony on Deneb V, Spock realizes that he has as little as three days to live. The cure for the disease is strobolin, which is found on only a few worlds in the galaxy, the closest of which, Beta Canopus, is four days away.

The U.S.S. Potemkin obtains the drug and transports it to the U.S.S. Huron, en route to the Enterprise. Without warning, the U.S.S. Huron is attacked by a vessel of Orion designation; the drug and a cargo of dilithium crystals are stolen. The U.S.S. Enterprise encounters the Orion ship in a volatile asteroid field by detecting the dilithium crystals in the ship's cargo bay. Kirk attempts to negotiate for the drug in exchange for not mentioning the stolen dilithium crystals, but the Orions' suspect a ruse. Kirk agrees to meet the Orion captain on an asteroid knowing that it might be a trap, but worth the risk for Spock's life.

The Orion captain arrives carrying a bomb capable of destroying the entire asteroid but Scotty beams the explosive to the Enterprise and discharges it. Scotty then beams up the two captains and forces the Orion captain to stand trial for piracy. With the medicine in hand, Spock is saved.

Cast:

William Shatner as James T. Kirk
Leonard Nimoy as Spock
DeForest Kelley as Leonard H. McCoy
James Doohan as Montgomery Scott
Nichelle Nichols as Uhura
George Takei as Hikaru Sulu

Guest Cast:

James Doohan as Transporter Chief
James Doohan as Captain O'Shea
Majel Barrett as Huron First Officer
George Takei as Huron Helmsman
George Takei as Orion Lieutenant
James Doohan as Orion Ensign
James Doohan as Lieutenant Arex
James Doohan as Orion Commander

Creative Staff:

Written By: Howard Weinstein
Director: Hal Sutherland