What exactly do you expect? The doctor and billie being killed for good in the first minutes? It's ALWAYS been about the doctor saving the day.

Wrong, several housemates were taken every 20 years only the most recent were restored.

So this was what, part two of three is it? These sort of episodes just don't seem to work well anymore. They used to be able to do these multi-parters OK, but not so much these days, it just feels like a filler before the 'real' episode, it doesn't stand on its own enough for me, you could almost miss these out completely and just watch the final episode without missing much.

Too many incidental characters coming in who serve no real purpose other than to be killed off before we get to know them - head of the UN or whatever he was,the 3 soldiers
Too many simplistic interpretations of human nature - the 3 soldiers supposedly represent the highest authority of the 3 biggest armies of the earth (yeah right, that's believable), and they simply shake hands and agree to peace when presented with an ultimate threat, yeah OK

Just felt like the old sloppy, simplistic, children's TV standard writing that has become too frequent in recent series, which was a shame as the earlier episodes weren't too bad, not stellar, but quite watchable. I was actually beginning to look forward to each new episode again, which I haven't done for a good couple seasons, but as we draw towards the big finale now, the big reveal, the dramatic ending, the master, missy, the doc regenerating etc etc, frankly, after this episode, instead of being on the edge of my seat, I'm losing interest again. It already feels like its going to be another over dramatised, botched, poorly written and strangely unsatisfying ending, trying far too hard to be clever with it's references to past episodes and events, and setting things in place for possible future stories, that it forgets to just be a good story in itself.

Hopefully I'm wrong