|Polly, Jamie, Ben, and the Doctor|
The aliens have a dastardly plot, and the Doctor and Jamie work to save Polly and Ben, who was also captured. Then Jamie gets captured, and the Doctor has to save everyone. Polly and Ben aren't on-screen much at all after the first two episodes. At the end of the final episode, they realize the current date is the day they left in the TARDIS, the beginning of their adventures with the Doctor. They're home, and they want to stay.
This story could've been improved by tightening it up a bit. It didn't need to be six parts. You could say that about a lot of the six-part stories, though. I like Polly and Ben, but I'm not sad to see them go. Their leaving makes room for great future companions- Victoria and then Zoe, who is one of my favorites.
Companions: Jamie, Polly, Ben
Episode: #35, "The Faceless Ones," six parts
Adversary: the Chameleons
Classic Lines: Jamie, on seeing a plane for the first time: "A flying beastie!"
Tuck This Away to Impress Your Friends: This is Polly and Ben's last story.
Next Up: "The Evil of the Daleks"