When the U.S.S. Enterprise answers a distress call from a small planet, the landing party is captured by a group of agents from the Kelvan empire, whose purpose is to find planets suitable for colonization. However, their own ship was destroyed and now they need the Enterprise to make the 300-year journey home to the distant Andromeda galaxy. To utilize the starship, the huge, tentacled Kelvans take on human form and use their technology to transform all but essential Enterprise personnel into small, dehydrated cubes.

James Doohan (Lt. Cmdr. Montgomery Scott)
Warren Stevens (Rojan)
Barbara Bouchet (Kelinda)
Nichelle Nichols (Lt. Uhura)
Majel Barrett (Nurse Christine Chapel)
Stewart Moss (Hanar)
Walter Koenig (Ensign Pavel Chekov)
Robert Fortier (Tomar)
Lezlie Dalton (Drea)
Carl Byrd (Lt. Shea)
Julie Cobb (Yeoman Leslie Thompson)