This was broadcast at Christmas, and ended with William Hartnell breaking character, and the fourth wall, to wish viewers a Merry Christmas.
This is the only Christmas special in the original 1963-1989 Doctor Who series.
This is the "ultimate" lost episode, as a film copy was never made.
This episode takes place in Liverpool, England on December 25, 1965 and Hollywood, California in 1921.
Reg Pritchard, who appears as "Man in Mackintosh" had previously played Ben Daheer in The Crusade, and the Doctor seemingly mistakes him for this character.