From the Radio Times:

5.40
DR. WHO
An adventure in space and time
starring
WILLIAM HARTNELL
WILLIAM RUSSELL
JACQUELINE HILL
and CAROLE ANN FORD
Day of Reckoning
by TERRY NATION
Title music by RON GRAINER
with the BBC Radiophonic Workshop
Incidental music composed and
conducted by FRANCIS CHAGRIN
Film cameraman, Pater Hamilton
Film editor, John Griffiths
Story editor, David Whitaker
Designer, Spencer Chapman
Associate producer, Mervyn Pinfield
Producer, VERITY LAMBERT
† Directed by RICHARD MARTIN
See page 9

Susan Forman leaves at the end of this serial.

This serial was made into a motion picture entitled Doctor Who and the Dalek Invasion of Earth 2150 A.D. starring Peter Cushing as the Doctor.