The first 4 episodes of the story were good. The Vardans could read most human beings' thoughts so the Doctor was under extreme pressure to outwit them and at the same time pretend to help them. This led to some great scenes with the Doctor showing a cold side to Leela and all other Time Lords - very unusual. Borusa and the Castellan showed the good and the bad side of Gallifrey and Leela was ready to gather help and fight the invaders. But thencame episode 5 and 6 - which brought the whole story down to an average rating. The Sontarans step into the breech when the Vardans are vanquished and we have many, many scenes of the Doctor and friends running down corridors (sometimes the same corridor!) and the Sontarans and Castellan fighting over and over again to stop them. The final scene with Leela staying behind with Andred is unexpected (and very unlikely) - it would have been better if she chose to stay with Nesbin and his tribe which would have been more in line with her character!