I thought it was a very good conclusion to the series.
The climax of the story was a bit fast for my taste, but to be honest, I cannot think of any other means at which it could have played out without harming the story and that is the only critical thing I can say about the story. It may also be related to that I may have missed it, and I truly think I did; as my son ran up and distracted me, but I feel as if the Master’s identity was alluded to but I couldn’t make the connection out.