Dr Who - The 3 Doctors - Feature Length - ( Sci Fi)- 1973

The Three Doctors is part, of the British science fiction television series Doctor Who. It was first broadcast in four weekly parts on BBC1 from 30th December 1972 to 20th January 1973.
Here it is presented as a feature length all episodes combined story
It was made to mark the 10th anniversary of Dr Who.

'Omega the creator of the Time Lords ability to travel in time, seeks revenge on the Time Lords after he was left for dead in a universe made of antimatter. The Time Lords recruit the First Doctor , the Second Doctor , and the Third Doctor to investigate. When Omega drains power throughout the universe, to escape his exile threatening all of existence.'

William Hartnell was very ill at the time, and his cameo was restricted to a few short appearances.