Möbius strip

The Twist in the 40th century. (COMIC: The Twist ^[+]Loading...["The Twist (comic story)"])

A Möbius strip, or Möbius loop, was a mathematical shape that had only one side.

To explain Möbian space to Adric, the Fourth Doctor took a strip of paper, twisted one end, and formed a loop, which created a Möbius strip. (PROSE: Conundrum ^[+]Loading...["Conundrum (novel)"])

The Twist was a colony ship in the shape of Möbius strip. (COMIC: The Twist ^[+]Loading...["The Twist (comic story)"])