Time Lord (The Three Doctors)

After a report on the "doomsday weapon" went missing from the Time Lords' files, a group of Time Lords (possibly, in retrospect, the Celestial Intervention Agency) decided to send the Third Doctor to the planet Uxarieus to investigate. Some time later the Time Lord assisted in a control room during the crisis that required the help of the first three incarnations of the Doctor.

Behind the scenes

 * Graham Leaman played the two Time Lord roles, who are quite likely the same character.