Okay, a couple of things right out of the gate.
First, yes, there was a time when Doctor Who was rather unabashedly geared towards kids. Over time this changed and the show became much more 'family viewing' but there was a time when it was very obviously playing towards kids. This doesn't mean that the stories were not good, just that they were a bit different than the fare viewers get today... or in the 1970's and later as well.
Second, I love Patrick Troughton, the 2nd Doctor. Even the stories he did that were crap were great simply because he was playing the Doctor. Troughton. Is. Awesome. That is all that needs to be said. So there's my bias on the table.
Now for one of my FAVORITE Doctor Who stories.... "The Mind Robber".
The Plot: While trying to escape the lava flow from an erupting volcano (picking up from the previous story, "The Dominators") the TARDIS malfunctions and the Doctor is forced to take drastic measures -- moving the TARDIS out of space and time entirely! While trying to make repairs the entire crew comes under the influence of a powerful mind. Companions Jamie and Zoe are lured out of the TARDIS and the Doctor comes under psychic attack. The Doctor manages to get his companions back but when he tries to return the TARDIS to normal space-time mysterious forces pull it apart!
The Doctor, Jamie and Zoe awaken separated in a strange wood. Jamie and Zoe fall into traps and the Doctor soon begins meeting with some of the strange denizens of this world. Wherever they are the usual laws of physics seems not to apply and the Doctor soon discovers that imagination and words seem to hold all the power here.
After rescuing his companions, the little group sets out and begins encountering strange, wind-up, toy soldier robots and characters from myth and story come to life. The Doctor soon realizes that they are trapped in a land of fiction and their only sure defense to to keep telling themselves that the things they encounter are not real.
The TARDIS team eventually makes their way to the "master" of this land and discover the sinister plot behind it all -- a computer brain creates the world but it needs imagination to give it the shapes of things to create! Having taken a writer from Earth decades ago the man is growing tired and now wants the Doctor to take his place since the Doctor is much longer lived. The Doctor refuses to become a slave to the machine but there are consequences as Jamie and Zoe are absorbed and become nothing more than fictional characters! Can the Doctor find a way out of this and save his companions or are they all destined to become a writer's toys?
My Take: It has long been argued among fans that Doctor Who is more Science-Fantasy than Science Fiction and this is pretty true -- certainly some eras more so than others -- but "The Mind Robber" is very, VERY firmly in the Sci-Fa rather than Sci-Fi camp. Despite this (or maybe because of it) what viewers get is a delightful, creative, imaginative and unique adventure story. It also created a story that was able to be delightfully stretched when the production ran into trouble.
You see, quite a bit of Patrick Troughton's era was rife with problems. Scripts were continually late and this, in turn, caused rushed productions and sudden shifting of story order. As a result, "The Mind Robber" had very little wiggle room -- it had to be filmed quickly and there were no other scripts ready which could be put in it's place if something went wrong. And something went wrong.... 23 year old Fraser Hines, who played Jamie, and one of his brothers, were renting a house together in London and decided to play host to their nephews over a weekend. What no one knew was that the nephews were contagious with Chicken Pox. Hines showed up on Monday for filming and soon broke out and was ordered home to quarantine. Since Jamie was in too many scenes to film around Hines's absence the only solution was to temporarily recast Jamie. A young, Scottish actor was found for the part and a clever bit of writing created a scene in the script in which the Doctor has to reconstruct Jamie's face and gets it wrong and then later has to reconstruct it again and gets it right as Hines was well enough to rejoin the production.
While all of this was a 'work around' for an ill cast member it ends up adding a delightful bit of fun to the overall story. It highlights and brings home the idea that this is a world where anything can and will possibly happen.
The cleverness of the script is also shown in much of the imaginativeness of the writing. For example, the character of Gulliver from Jonathan Swift's Gulliver's Travels speaks only lines from that story. Rapunzel turns out to be quite used to people using her hair as a rope all the time and we are even introduced to a comic strip superhero from the future. A 'forest' turns out to be made of giant letters instead of trees and the letters all spell out common sayings, wind-up toy soldiers chase our heroes throughout the story, and Jamie and Zoe are pressed inside a giant book like flowers and become "fictional" characters. This is another part of the charm of the story; watching as an adult you become aware of the irony of the fact that the Doctor and his companions are already fictional characters.
For the most part all the performances are also just delightful. Of the supporting cast the "Master" writer is a bit too plummy at at times and his attempts to use a different voice when speaking as the computer brain don't always come off well but the script does a good job at keeping his true nature hidden until the very end. Also, throughout the story the viewer is led to think of him as the villain of the piece only for it to be revealed that he is not the bad guy we have thought him.
Bernard Horsefall would go on to guest star several times in Doctor Who but he makes a lovely Gulliver here. His voice and delivery of the lines made me wish there was an audio book of him reading Gulliver's Travels. He delivers the old-fashioned language without flourish or embellishment -- making it seem downright conversational.
Of the main cast, there are a few moments where Fraser Hines overacts a bit and Wendy Padbury's screams are sometimes over the top and are also done for no good reason at times. Aside from that, though, Hines makes Jamie charming, brave, and exasperated by turns and Padbury's Zoe presents viewers with the prototype of the modern, female companion -- intelligent, quick-witted and actually a bit tough. It must be said, though, that Zoe's fight with the superhero Karkus looks a bit bad on-screen. In the cast commentary Padbury explains that there was very little time to rehearse the fight, she had never done a fight scene before and there was no time to re-shoot the scene to cover some of the worse gaffes.
Troughton is also his usual, solid self here. His Doctor is a mercurial sort -- going from defiant to befuddled, to fearful in split seconds. There is also a slightly chilling moment as the Doctor refuses to take the writer's place -- not even to save his companions. We see, in a later scene, that the knowledge that his companions are lost to him pains him deeply but he refuses to give in even for them. The battle of imagination between the Doctor and the writer is also fun as famous characters from myth and legend appear and disappear to battle at the very thoughts of these two determined people. There are also some great lines of dialog as the Doctor baits and insults his opponent.
With an extremely inventive script, witty dialogue, nice acting performances all around, "The Mind Robber" is Doctor Who at it's best. The story shows just how malleable the format could be -- stretching the bounds of the series to date. Sure, some of the story seems a bit simplified and appealing to kids and some of the special effects don't hold up as well but the sequence of the TARDIS breaking up is still shocking today and provides one hell of a cliffhanger for the first episode and there are moments taken very seriously -- like where we see the Doctor seemingly defeated and out of options. Overall, while I wouldn't necessarily want a steady diet of stories like "The Mind Robber" as it stands it is a breath of fresh air, a view askew of the Doctor's world, and a look at what the show could potentially pull off.
Fans of Steven Moffat's current run on the show should definitely check this one out -- I think they'll find a lot in common.