While observing a burnt-out supernova, the U.S.S. Enterprise picks up a strange message transmitted in a two-hundred-year-old code. The crew of the Enterprise begins to shrink when a paralyzing light flashes throughout the ship. Rapidly, decreasing in size, the crew must find a way to reverse the effect and find out who's responsible before their ship becomes too big to operate.

William Shatner (Captain James T. Kirk)
Leonard Nimoy (Commander Spock)
DeForest Kelley (Dr. Leonard H. McCoy)

George Takei (Lt. Hikaru Sulu)
Nichelle Nichols (Lt. Uhura)
Majel Barrett (Nurse Christine Chapel)
James Doohan (Lt. Cmdr. Montgomery Scott)