 "Universe" was also performed as a radio play on the NBC Radio Network programs "Dimension X" (on November 26, 1951) and "X Minus One" (on May 15, 1955).Those versions have several drastic changes to the story, especially in their conclusions in which Hugh is killed, showing the crew of the "Vanguard" the true nature of the Ship.Two-headed humans exist, one variation of conjoined twins.