Dr Who and cutting for pace

I had been really looking forward to last night's episode of Dr Who but was disappointed. My husband who is also a fan expressed his disappointment. The pace slowed to a crawl and the tension was really not there because that particular story didn't progress.
There was little development between River and Dr Who to justify the whole Amy walking amongst the angels.

It is like anything carried too far. With nothing added to the mix, the story stalls and ceased to be frightening, just becoming a...