M. C. Escher

Maurits C. Escher was an artist famous for creating confusing engravings. (AUDIO: The Forever Trap)

Graham Stevens had an array of Escher prints in his office. (PROSE: Cat's Cradle: Witch Mark)

The Seventh Doctor told Ace that she did for the English language what Escher did for spatial geometry. (PROSE: Lucifer Rising)

Laura Corbett said that the Land of Fiction was "very M. C. Escher". (AUDIO: The Crooked Man)

The Tenth Doctor compared the Edifice to "the steps that go up and up and join up". (AUDIO: The Forever Trap)

The Eleventh Doctor, while trapped in the Bank of England, jokingly remarked that it was designed by Escher. (GAME: The Eternity Clock)