After his three years were done, Robin Williams ultimately left the role of The Doctor. The ratings and audience reception was good so the producer wanted to do something very risky: start the next incarnation of the Doctor as unlikeable and make him more likeable as time went on, and make him a dark figure. With this, Christopher Walken was cast, who ultimately loved the show and was happy to be a part of it. Walken wasn't a huge fan of the direction they were going in, but loved the character so much, he agreed to it anyway. With this, Christopher Walken as the Sixth Doctor begins.
