Edge of Destruction (1.7)

Squashed between two seven episode classics, 'The Daleks' and 'Marco Polo', 'The Edge of Destruction' is often overlooked, and perhaps that is for the best. It is filler material for the season and it was written with severe production constraints, but neither of these facts can excuse the fact that the writing is really poor and nobody - cast, crew and audience - seems to know what's going on.

Leaving Skaro behind, the TARDIS suddenly breaks down. The formidable four black out briefly and when they recover they find themselves plunged into a psychodrama flavoured with amnesia, paranoia, hallucination, imminent danger and general hysteria.

The Majesty
The set-up here is actually really good: some inexplicable situation has arisen which is causing the TARDIS to malfunction and the crew to behave as if under some kind of mental attack. After the dull Thals and duller Cavemen, it's nice to spend significant amounts of time with the Doctor, Susan, Ian and Barbara. There is acknowledgement of everything that has happened from the beginning of the show onwards; there is some attempt to unravel the tensions within the group. In particular, Barbara's relationship with the Doctor is brilliantly pugnacious and their final reconciliation feels very genuine. There is a rare sense of character development in this story.
It is typical to berate the cast for bad acting in this story, and it's hardly perfect, but I think there should be kudos to them for making the best of a bad job when given lines such as Barbara's: "Time was taken away from us, and now it's being given back because it's running out". 
I'm even going to go out on a limb here and say that Susan turns in a remarkable performance in the first half of the story: from the moment she picks up the scissors, she would fit right in on 'Night of the Living Dead'. Having her wandering the ship with a vacant expression, scissors in hand, does a lot to increase the tension.

The Misery
It all falls apart. I said this before about 'An Unearthly Child' but here it falls faster and further. There is absolutely no coherent plot or structure or development; the resolution, when it comes, is both pathetically trivial (a sticky button) and completely unsatisfying; Susan's acting in the second half destroys any kudos she built up in the first half, and we are left feeling very frustrated.
There was a chance here to tell any of a number of different stories, and maybe this was the original intention: (1) an alien intelligence has infiltrated the TARDIS - it could be anyone at any time; (2) the TARDIS is in some form of danger, and is psychically reaching out to the minds of the crew in an attempt to communicate this; (3) the crew are getting cabin fever after being stuck with each other for so long. Paranoia and conspiracy abounds.
Any one of these stories could have made for an excellent 2-parter, but 'Edge of Destruction' opts for telling little bits of all of them and not actually telling any of them properly. 

Magical Moments

• Susan - a psycho zombie - stabs the couch with scissors again and again and again. 
• Susan wonders if an alien intelligence has boarded the TARDIS. Barbara - "Where could it hide?" Susan - "In one of us"
• That special moment when Susan and Barbara look at the scanner, and, in clear reflection, we see not just the boom mic, but the whole sound recordist running across the stage to catch the dialogue.
• The Doctor drugs everyone, turning up like a sinister butler with little plastic cups. As everyone collapses into sleep, he delivers a full-blown cackle.
• The lights go out in the TARDIS, the Doctor leans against the console, soliloquises eloquently about the formation of the solar system, and then literally tries to chew off his knuckles.
• In a shameless Art Department fail, the Fast Return switch is marked by the words 'Fast Return' written on the console in felt-tip pen. 

In Summary
It may be the first hint that the TARDIS is alive (as we eventually discover in the days of Matt Smith). There again it may not. Whatever it is, it is at least mercifully short. The main problem with this story is a missed opportunity to actually tell a story, substituting atmosphere and mystery for anything resembling a plot.

Overall 1.7