The Master (Exile)

In a parallel universe, the Master used many fake names, including Roger, Peter, Geoffrey, Tony, Eric, Robert and Sam. A parallel universe version of the Doctor mistook Bob for the Master and used Venusian aikido on him. (AUDIO: Exile)

Behind the scenes

 * The pseudonyms that the previous Doctor attributes to the Master are "Roger, Peter, Geoffrey, Tony and Eric, Robert and Sam." This is a reference to the actors who played the character of the Master at the time: Roger Delgado, Peter Pratt, Geoffrey Beevers, Anthony Ainley, Eric Roberts and Sam Kisgart.