Doctor Who: The Best of The Third Doctor Season 1 Episode 8 The Three Doctors, Episode 4

The Three Doctors is the fourth and final episode in the first season of Doctor Who: The Best of The Third Doctor. This episode sees the return of the first two incarnations of the Doctor, played by William Hartnell and Patrick Troughton, as they team up with Jon Pertwee's Third Doctor to save the universe from destruction.

The episode begins with a mysterious energy drain that threatens the fabric of time and space. The Time Lords, the race of beings to which the Doctor belongs, decide to call upon the help of all three of the Doctor's incarnations to solve the problem. The First and Second Doctors are brought to the Time Lord's home planet, Gallifrey, where they meet the Third Doctor.

As they work together to solve the problem, the three Doctors find themselves facing off against their old enemy, the renegade Time Lord known as the Omega. Omega was believed to have been destroyed long ago in a supernova, but it appears he survived and has come back to seek revenge against the Time Lords.

The Doctors soon discover that Omega has created a black hole, which he plans to use to escape his exile and regain his power. The only way to stop him is for one of the Doctors to go through the black hole and confront him directly. The Third Doctor volunteers for the task, and with the help of his past selves, manages to stop Omega and close the black hole.

In the end, the First and Second Doctors return to their own time periods, and the Third Doctor is left alone once more. However, the experience has taught him the importance of working with others to solve problems, and his relationship with the Time Lords is left on a positive note.

Overall, The Three Doctors is a classic Doctor Who episode that features an incredible team-up between the first three Doctors. It's a must-see for any fans of the series, and is a great example of the show's ability to combine science fiction, adventure, and humor in a way that few other shows can.