Mission to the Unknown - S3-E2
Plot hole: The Daleks announce their secret plan on the city's external loudspeaker system, where Cory hears it. It can hardly be a 'secret' plan if it is broadcast for all to hear...
Plot hole: It is highly unlikely that the discovery of a dead down-and-out's body in an empty warehouse would be reported in a national newspaper, especially as the discovery had to have been made when the newspapers were already being printed.
Answer: TARDISes are generally available for properly authorised use on Gallifrey; they're not usually assigned to a particular Timelord on a long-term basis. The Doctor stole his when he left his homeworld.
Tailkinker ★