This story sees Troughton's first real direct conflict with authority figures. He's had some conflict before, particularly in the last story, but there the Pilot was rather ineffectual as a leader. Here he's up against the Commandant, who can more than hold his own. We also see the first real interplay between Jamie and the Doctor, as the Doctor repeatedly elbows Jamie as he blurts out things about the TARDIS. And set against this, the murder mystery with the airline pilots from Chameleon Tours who are definitely not of this Earth is proceeding nicely, as they first kidnap Polly and then bring a strange being to the medical facility: an eponymous "faceless one"...
Episode 2 continues the fun, as Polly reappears but apparently knows nothing of the Doctor or Jamie. So we get another possession of a companion, but this one doesn't even have something for Polly to struggle against, since it seems to be Polly but not Polly. Then there's some fun in a photo booth, as the Doctor and Ben flash cheesy grins at the camera while they work out their next move; Jamie looks completely confused, wonderfully. Meanwhile the "faceless one" gains a face, as it appears to take on the appearance and identity of one of the air traffic controllers -- a creepy idea, especially when you realize this must be what happened to Polly as well...
Then the Doctor goes to clash with the Commandant some more about Chameleon Tours, while Jamie meets up with plucky Liverpudlian Samantha Briggs, who's investigating the disappearance of her brother on Chameleon Tours. And then Ben is kidnapped by the Chameleon Tours people too! It's a fun, exciting episode, with an intriguing mystery and enough incident along the way to keep the audience tuning in. So far so good.