Note: First appearance under this title in Ace Double 1959 with The World-Swappers by John Brunner.

Synopsis: From the first page of the Ace Double: "The three eyes of evil - The crash was over, the car on its side. Slade sprawled dizzily on his back, while something warm trickled from his forehead into his left eye. He wiped it away, and saw with a start it was blood. The skin was torn raggedly... "A third eye was plainly visible. The eyelid of it was closed by a surplus of sticky matter, but abruptly he grew aware that it was pulsing with a vague perception of light..." At first it was a grotesque discover, when the accident revealed that young businessman Michael Slade was a bizarre freak - a man with three eyes. But the impact of what it meant to see with three eyes was even more macabre. For Slade, that shocking third eye was his entry into a strange new dimension of terror and adventure - a fearful new world that would wrap itself about him forever!"