I'm finding myself agreeing with all the dissenters. The story was really only okay, and very pedestrian. The monsters were unusual but have to agree with TEIN about the water-jets. He mentioned the Ice Warriors more than once, so I thought maybe they turn into Ice Warriors, but instead they just spouted more water.
The end became interesting and I could also have believed and gone for a spell with a much darker Doctor, but it was a reset button moment. The Doctor has long wanted to interfere, and he always has on a small scale. That is what he does every week. It was the Time Lords that prevented him making major changes, punishing him as they did in 'The War Games' for his meddling. Also, if you had believed in something like 'unmovable fixed points in time' for 900 years, you would also find it hard to change your mind. But there is no one left to tell him what to do, and he can do what he likes. Pity, it was just instead a recap of the last series and trailer for the next two episodes.
The end became interesting and I could also have believed and gone for a spell with a much darker Doctor, but it was a reset button moment. The Doctor has long wanted to interfere, and he always has on a small scale. That is what he does every week. It was the Time Lords that prevented him making major changes, punishing him as they did in 'The War Games' for his meddling. Also, if you had believed in something like 'unmovable fixed points in time' for 900 years, you would also find it hard to change your mind. But there is no one left to tell him what to do, and he can do what he likes. Pity, it was just instead a recap of the last series and trailer for the next two episodes.