Doctor Who - The Three Doctors

"The Three Doctors was the first serial of season 10 of Doctor Who.The serial marked several milestones for the program. Most notably, it was the first multi-Doctor story, establishing the concept of the Doctor being able to meet his past incarnations. As such, it also marked the return of William Hartnell and Patrick Troughton to the roles of the First Doctor and Second Doctor respectively. Narratively, this tenth anniversary special also ended the three year long story arc of the Third Doctor being exiled to Earth, which had begun in season 7 in 1970. Additionally, the special saw Brigadier Lethbridge-Stewart and Sergeant Benton enter the Doctor's TARDIS for the first time. It was incidentally the first use of the phrase "it's bigger on the inside than it is on the outside," notably by the Third Doctor as a suggestion for what Benton should say."
 
This 1991 release of the story is in good condition