Finally made my way through all of Reign of Terror. Ugh. It was a stinker, in my opinion. They spent six episodes with some variation of "Companion gets captured and stuck in a jail cell. Companion is released/escapes. Companion gets captured and stuck in a jail cell again. Rine and repeat." I did one episode per day, and I think if I had tried two, it really would have been too much. I just did not enjoy this story.
Others in the same era - Planet of Giants, Sensorites, Aztecs, Dalek Invasion, I don't remember having that problem.