No sooner have we entered our mini-arc than we practically take a break from it. This story doesn't have Sam in it at all; being instead a return for the Doctor to post-Dalek Earth and Susan. Featuring both hidden Daleks and human internecine war inflamed by the Master there is a little something for everyone. In the end it provides some closure for both Susan and the Master, who gets lined up for where we find him in The Eight Doctors.
This is a well written, solid member of the series; but rather irritating because you want to know what happens to Sam.