A group of scientists experiment with a new missile that will produce vast amounts of light at night. The experiment fails and the scientists have to figure how to shut the light off.
Did You Know?
This was DeForest Kelly's first appearance in a science fiction show, other than his previous appearance in the earlier story, "Y..O..R..D", in the same series. He would later go on to the career defining role in Star Trek as Dr "Bones" McCoy. See more