A ‘bottle’ story made up of two episodes, set entirely in the Tardis, with some sort of technical fault at work, and everyone (over-)acting weirdly. Concludes with a rather unremarkable solution (the button was pushed in!).
I suppose at this point, this could be seen as a much-needed chance to develop the characters, but when those characters are behaving so weirdly, it amounts to an uncomfortable couple of episodes that still feel like filler.
I wouldn’t say it was entirely without merit. There’s a uniquely eerie mood throughout the whole thing. It also gives us our first glimpse at some of the other rooms inside the Tardis – it would appear to be quite well-equipped! It also shows us just how fragile the equipment is if it can go so easily wrong, but hints at some self-awareness or self-preservation within the machinery too.
I don’t really have much to say about it aside from that. The Tardis is fixed and lands somewhere cold… so, onward to the next adventure!