watch 01:38 The Loop (TV) Do you like this video? The Fourth Doctor, Leela and Idas in tunnel seven. (TV: Underworld) Tunnel seven was a location on the planet P7E. A "skyfall" had occurred there prior to the Fourth Doctor's arrival and several Trogs had been killed. (TV: Underworld) Retrieved from "https://tardis.fandom.com/wiki/Tunnel_seven?oldid=2989703" Categories: Tunnels + cat Cancel Save Community content is available under CC-BY-SA unless otherwise noted.