The Factory (The Light at the End)
From Tardis Wiki, the free Doctor Who reference
The Factory was the location where the Vess sold their weapons to other races. It was a pocket dimension that drew energy from Event One. It was the most closely guarded secret in the universe, accessible only by invite. The Decayed Master used it as a base of operations after he discovered that Straxus was involved in secret deals there, blackmailing Straxus into allowing him to take a conceptual bomb to use against the Doctor. (AUDIO: The Light at the End)