First Doctor - Seventh Serial
7 Episodes, Companions: Ian, Barbara, ans Susan, as before.
Summary: The TARDIS materializes inside a moving spacecraft from the 28th Century, to find the crew dead - only they aren't, they're suspended by the Sensorites, a group of aliens from the SenseSphere that won't let them escape. They discover that the Sensorites are not precisely malicious, but they distrust the Humans, who want to mine their planet for Molybdenum. The Sensorites steal the lock for the TARDIS, trapping the companions outside, and forcing them to deal with the Sensorites to get their ship back. They become embroiled in solving the cultural ills (and actual illnesses!) of the SenseSphere to gain the trust of the homosapienphobic Sensorites, and get tangled up in an ugly power and political dispute.
The Doctor: It's a good chuckle when he claims to be opposed to interfering in other cultures, although at this point he really has only interfered to save his companions. Finally, a Serial where he shines! He's the driving force behind the investigation and solution of most of the situations. Everything from the Molybdenum to the toxins in the aqueduct, finally the Doctor is an active member of his self-titled show.
Companions: This time, Barabara isn't the star! She's not present for most of the 7 episodes, and without her presence, Ian and Susan get a little more development. Ian still shines as the most observant of the pair of them, but Susan takes on a new importance as the ambassador with the Sensorites, due to her telepathic receptiveness. This Serial has the least unneccesary capturing, escaping and recapturing of the companions to date. That's hyperbole, becuase I haven't actually been counting, but I think they only get trapped twice, and spend the other 5 episodes solving the problems before them, and getting embroiled in newer problems instead. Brilliant!
Continuity: A sonic Screwdriver would have solved half of the first episode. We also learn here that Susan has latent Telepathic powers - or at least is more receptive to telepaths and empaths than the others are. Oh - and The Doctor makes a reference to his "heart". Singular. Just sayin'. We also learn that the as-yet unnamed Home Planet of the Doctor and Susan has silver-leaved trees and a burned orange night-time sky. Susan indicates that she'd like to go home, someday, and The Doctor indicates that he's not able to control the TARDIS very well, giving the impression that rather than being exiles, they are lost in space. It's not directly stated, and Ian and the Doctor argue about that very thing at the end.
Rating: Bear it. This one's not as strong as most of the previous ones, but the Doctor's change to activity, and Susan's useful role make this one worth the time. I've been waiting for Susan to get a good role, and this one comes pretty close. As a negative, I found the Sensorites unsympathetic, so while most of the time the Doctor was trying to help them, I really didn't care that much. Even though there were really only two evil Sensorites, they were insipid and had such a kindergarten kind of petty evil I found they tainted the whole race. Upon my second viewing though, I came to like the First Elder and the companions in this one, so it's better than the Keys of Marinus. And it suffers form being just too many parts, the six parter could have stood trimming - it could have easily been told in four.