The Rescue

Following on from the Dalek Invasion of Earth is this short two-parter, which serves only as a means to replace Susan with the much less annoying character of Vicki. This serial accomplishes this well, and Vicki bonds with the Doctor straight away. Her relationship with Barbara does develop lots in the two episodes and some of the dialogue shared between them is excellent.

As for the plot, it isn't the most important aspect of the story. There's a small cast, and a tiny sense of unease about the planet of Dido. A plot twist added near the end of the second episode is welcome, but the plot isn't wrapped up properly. You don't really notice all the errors though with all the great acting and dialogue. It's a little obvious that this serial offers breathing space after the intense and epic adventure of the Dalek Invasion of Earth. 

The Rescue is worth watching purely for the dialogue and character interactions, which are all superb. Even if you don't pay much attention to the story progressing, it's still an enjoyable fifty minutes.