22. The Massacre of St Bartholomew's Eve

After the death and blood-shed with the Daleks last story, the Doctor seeks out some quiet, peaceful time. Unfortunately the TARDIS has other ideas and lands in 1572 Paris, during hostilities between the Protestants and Catholics and on the eve of another Massacre.

None of the four episodes of this story exist which is a shame as this is another fantastic historical story. With the death of Katarina and Sara, Steven is the sole companion with the Doctor and a rare moment when there are just men in TARDIS.

In the final moments of the story, we are introduced to Dodo Chaplet as she bursts into the TARDIS. Meant to be a modern day descendent of the stories main character Ann Chaplet, Dodo gets a proper introduction next story.

en.wikipedia.org/wiki/The_Massacre_of_St_Bartholomew's_Eve

Next thrilling episode: The Ark!

21. The Daleks' Master Plan

The Dalek's Master Plan was a giant 12 episode story that once again brought back the Doctor's greatest enemy and once again, changed the Doctor's life forever. Of the 12 episodes, only 3 episodes still exist today, as released on the Lost in Time special DVD.

From these few remaining minutes of precious footage, we get to see our new companion Katarina, Doctor Who legend Nicholas Courtney in his first role as Bret Vyon, Jean Marsh back as Sara Kingdom, the second appearance of the Meddling Monk, and Kevin Stoney as Mavic Chen. A cavalcade of stars! We also get to see more Daleks than ever before and a whole host of aliens, the likes of which we won't see again until 2005's episode The End of the World.

As with the last two appearances of the Daleks, this meeting has even great consequences for the Doctor. When the Daleks invaded Earth, the Doctor's granddaughter left. When the Daleks chased the TARDIS across time and space, Ian and Barbara returned home. This time, due to the machinations of the Daleks, both Katarina and Sara Kingdom die. Katarina sacrifices herself by blowing herself and an escaped convict out an airlock to allow the Doctor and Steven to escape. and Sara ages to death because of the Dalek's Time Destructor. It's not for another 15 years that the Doctor's companion dies (see Adric in Earthshock).

It is a shame that this epic story doesn't exist in its entirety. While the complete audio exists and provides us with ability to hear this wonderful story, it doesn't do the visuals justice. We see so little of Sara Kingdom and even less of Katarina, these lost companions. That is the real tragedy.

en.wikipedia.org/wiki/The_Daleks%27_Master_Plan

20. The Myth Makers

The Myth Makers must have been an amazing story to watch. Unfortunately this is another story where none of the video exists.

In this story we saw Vicki depart the TARDIS because she fell in love with a Troilus and the Greek handmaiden Katrina joins the Doctor and Steve in his "blue temple".

The surviving audio recording of the story is a joy to listen to. Sweeping landscapes.Greek tragedies. Love on the battlefield. And as usual, mortal danger for our TARDIS crew.

en.wikipedia.org/wiki/The_Myth_Makers

19. Mission to the Unknown

Mission to the Unknown was a one-episode prequel to the forthcoming mega story The Dalek Masterplan. It is unique in that none of the regular cast appear in it and it aired 5 weeks prior to the Masterplan. Unfortunately this episode no longer exists.

en.wikipedia.org/wiki/Mission_to_the_Unknown

18. Galaxy 4

Galaxy 4 kicked of Doctor Who's third season. Unfortunately for many years, all footage was lost until last year when one episode was finally found. That episode is to be released in March at that point, I shall write a review.

en.wikipedia.org/wiki/Galaxy_4

UPDATE 3/20/13
Released with a special edition of The Aztecs, the newly discovered 3rd episode of Galaxy 4 is an extra special extra feature. Nestled within a telesnap reconstruction of the story with the original soundtrack, the episode is a highlight of the piece. It really is a joy to see a NEW episode of LOST Doctor Who. From the extant surviving material, the story presents an interesting gender play and a parable on don't judge a book by its cover. I probably would not have chosen this story to launch the season but with the Dalek Masterplan a few stories away, it was a quieter beginning to a monumental season of Doctor Who.

17. The Time Meddler

Our intrepid TARDIS crew has reached the end of their second season. When we started this sophomore season, we had all of our original crew with the Doctor, Susan, Ian and Barbara forming a close family unit after the harrowing adventures of the first season. Over the course of season two, the Daleks reappeared twice and each time, the Doctor lost companions. In our last adventure, Ian and Barbara departed the Doctor in the Dalek time machine to return to their proper place in time and space. In this final adventure of the season, we welcome a new addition to the TARDIS and meet a new adversary.

Rescued from the Mechanoid stronghold on Mechanus, Steven Taylor stumbles into the TARDIS and joins the Doctor and Vicki on their journey. Landing in a Saxon village in 1066, Steven initially doesn't believe he has traveled in time, as they find several anachronistic items littered about. We are introduced to the Meddling Monk, who apparently is a member of the Doctor's as-yet unnamed alien race and he possesses a TARDIS of his own! While the Doctor adhere's to his people's rule of not interfering in history, the Monk takes great delight in breaking the rules for his own personal gain.

It's interesting to learn a little more about the Doctor's past but not much. We only see the Monk once more in the show's 50 year history and it takes another 4 years before we learn anything more of the Doctor's people. The Monk could be considered a very primitive prototype for the Master. This is also the first time we see the Doctor's TARDIS envy.

In the end, the Doctor defeats the Monk, booby traps the Monk's TARDIS, and history is saved. Our newly christened TARDIS team of the Doctor, Steven and Vicki depart for new adventures in time and space. The next season of Doctor Who will bring changes to the Doctor's life and TARDIS crew on an almost exponential scale and the constantly changing trajectory of the show continues. Unfortunately many episodes of the next three seasons are missing and presumed destroyed. This season two is the most complete season until we reach season six.

Now 2/3rd the way through his tenure as Doctor, you can see William Hartnell visibly aging and flubbing his lines more. While he's still pretty spry and engaging in hand to hand combat, he is slowing down. In his final season, both the Doctor and William Hartnell will face his greatest challenges with stunning victories and the deepest of defeats for years to come.

en.wikipedia.org/wiki/The_Time_Meddler

16. The Chase

The Daleks once again return to wreak havoc on the Doctor's life and once again, the world of Doctor Who is never the same again. Last time we encountered the Daleks, the Doctor's granddaughter Susan left. This time, the Doctor is able to return Ian and Barbara to their proper place in time and space via the Dalek's time machine. And with that, all of the Doctor's original companions have departed. The parting moments are played with great emotion, with the Doctor genuinely saddened but understanding their desire to return home.

This story is a jolly romp, hopping around all of time and space, as the Daleks "chase" the TARDIS crew to various times and locations. We see the Empire State Building, the Marie Celeste, and Frankenstein's House of Horrors. Our last stop brings us to Mechanus where we meet the Mechanoids, large giant rotund robots who give the Daleks a run for their money.

In the final episode, we are introduced to Steve Tyler, our new leading man. He'll get a proper run through next episode. But with Ian and Barbara gone, Vicki still with the Doctor, and Steven coming in, the show begins a new chapter for the Doctor and the pattern of constantly changing companions truly begins.

en.wikipedia.org/wiki/The_Chase_(Doctor_Who)

Next exciting episode: The Time Meddler!!