Edge of Destruction
As I recall, at the end of the previous story there is an explosion. This explosion knocks out the TARDIS crew. The fact the crew is knocked out leads to plot of the next story in Doctor Who. From my standpoint and what I can conceive. The explosion which takes place causes the crew not to travel anywhere, which means thy spend the whole story in the TARDIS.
I don’t know how the people of 1964 actually take this episode, but personally I am not a fan of such stories on Doctor Who. I can say it is better than one of David Tennant’s stories which takes place in the TARDIS. The fact that the Tenth Doctor does not appear physically takes away from the show. All anyone sees is a recording from him. That is not something I liked.
After reading the information on this story, I do seem to remember watching it one time. But like I said, I am not a big fan of this. The idea of the Doctor being suspicious of Ian and Barbara is not something new. The Doctor overall is always suspicious of just about everyone and everything. So, I see where he does not trust them, but in this story there is reason. The Doctor now trust both Ian and Barbara and does not have a reason to do what he does.
Well, the whole crew suffers injury because of the explosion. The effects of being knocked out is that the crew members have amnesia and they action become peculiar.(1) This strange behavior cause the Doctor to drug Ian and Barbara. I am guessing to render them helpless until he can figure out what to do, from what I read he does this because of suspicion of wrongdoing on the part of Ian and Barbara. Well, this suspicion is not only something we see in the Doctor. The whole crew has the same suspicions.
At this point, the Doctor believes he is the only one capable of finding the problem. This is why he drugs Ian and Barbara. He wishes to deal with the problem himself. His feeling and possibly those of the crew is that one of them is trying to sabotage the TARDIS.
Barbara seems to be the only sae on at this point. She uses deductive reasoning and gathers clues which helps the Doctor trace the problem back to a broken fast return switch.
The Doctor is suppose to be the genus right, so why did he not see this coming. This only proves that he is much better when travelling with companions. Barbara proves to the Doctor she can be trusted and that he needs her.
Now, the Doctor does have to eat his words. He is very disrespectful and mean to Ian and Barbara and mus apologize for his behavior. From all I have ever seen of the First Doctor, to get him to apologize is like pulling teeth. He is a grumpy old man who does not like being wrong.