Spatio-temporal hyperlink

A spatio-temporal hyperlink was what the Tenth Doctor called a connection between the SS Madame de Pompadour in the 51st century and 18th century France - "it's better than saying 'magic door'." It had been established by the Clockwork Droids in their quest for "spare parts" -- specifically, the brain of Reinette. (TV: The Girl in the Fireplace)