Who's Who? (comic story)

Who's Who? was a Third Doctor comic story published in the Doctor Who Holiday Special 1974.

Summary
Sarah Jane distracts the Doctor while he repairs the TARDIS, which causes the pair to be transported to an alternate Earth where their counterparts are dangerous criminals!

Characters

 * Third Doctor
 * Sarah Jane Smith
 * The Doctor
 * Sarah-Jane
 * Motorist

Worldbuilding

 * The Doctor's cottage exists in both Doctors' universes.
 * The Doctor refers to his current repairs of the TARDIS as a sort of "ten-thousand year service". The temporal equivocator is low on liquid mercury.
 * The Doctor states that cars with solar powered engines won't exist on Sarah Jane's Earth for another century. At least one such engine exists in the first parallel Earth.
 * Edward IX is king of England in the first parallel Earth.
 * The Bank of England exists on the parallel Earth.

Continuity

 * The Doctor previously met counterparts of individuals from his reality on a parallel universe known as the Inferno Earth. (TV: Inferno)