The Pirates of Orion
09/07/74 -- Stardate: 6334.1
Spock contracts a disease that is fatal to Vulcans, and Orion pirates make it difficult
for the Enteprise to rendezvous with a freighter that is carrying the only known antidote.
09/14/74 -- Stardate: 7403.6
On a series of exploratory missions with Bem, a Pandroan representative, the Enterprise
encounters a planet of primitive natives under the guardianship of an advanced race; but
Bem tries to put the Enterprise crew to a test of loyalty to his planet and in so doing,
causes problems with the guardian race.
09/21/74 -- Stardate: 3183.3
While trying to escape from three Romulan warships, the Enterprise passes through a
gaseous cloud that affects the Enterprise's computer and turns it into a dangerous
09/28/74 -- Stardate: 5275.6
Returning to a planet where McCoy headed a mass-innoculation program against Saurian
virus 19 years earlier, the Enterprise crew find that McCoy is wanted for starting a
plague that killed most of the planet's population after that earlier visit.
How Sharper Than a Serpent's Tooth
10/05/74 -- Stardate: 6063.4
The Enterprise encounters a ship in the shape of a winged serpent, which turns out to
be Kukulkan, a god of ancient Mayan-Aztec legend, who wants the humans to worship him as
the Mayans and Aztecs did.
The Counter-Clock Incident
10/12/74 -- Stardate: 6770.3
While transporting Commodore Robert April, the Enterprise's first captain, and his wife
to Babel, the Enterprise plunges through a nova and into an alternate universe where
everything is backwards, and the crew begins to grow younger at an accelerated rate.