I was fully expecting that everyone was trapped in a networked dream state in the new Morpheus machines. The Sandmen in this plot in my head were people who had been consumed by and added to the growing intelligence in charge of the network. Ergo the failing gravity shields would have been an effort to force everyone to wake up.
Yep, that's where I thought they were going with it too.... But, I was hoping, once he figured out that it felt more like a "story" that he had accidentally landed in the land of fiction, again. It'd be so great to get a land of fiction story in the new series... and the Capaldi Doctor would be a hoot in it.
My wife kept commenting on how the episode felt more like a Big Finish audio than a TV episode... And it seemed familiar to me, too.
Was this episode a re-write of "Dust"?