I'm with you completely. What starts out as a seemingly 'run of the mill' episode - and I don't mean that in a bad way; even 'run of the mill' Who is generally pretty good! - turns into something utterly amazing in those last few sequences. I never expected the watch either - which is what made it such an incredible reveal; I think I was holding my breath after that to see what would happen!

The Doctor and Jack dynamic is one of the best things in the episode - and that's saying a lot, because there's a lot of great stuff packed in.