The Enterprise responds to a distress call from the planet Scalos, but when Kirk and a landing party beam down to the planet they find no living beings. It turns out that the Scalosians live at a much higher rate of acceleration, rendering them invisible to the human eye. One of the Scalosians, the beautiful and seductive Deela, accelerates Kirk so they can interact, where she tells him he cannot return to his normal life. For the crew, Kirk has virtually disappeared before their eyes. The Scalosians want to turn the Enterprise into a cryogenic storage facility for the crew. Kirk learns that at his current state of acceleration, they are subject to cellular degeneration and rapid aging should they suffer the slightest cut. He leaves a message for the crew but it is left to Mr. Spock to find a way to decipher it.