On the Whispermen:
"the thought of stylish whispering almost faceless creatures was an idea that
firstly scared me and that I thought would work well in an episode that looks
forward and back."
Talking about the plot and Clara:
"It’s full of surprises and questions that have never been answered in the
history of Who, including the Doctors greatest secret. We’re not
pretending, we’re not kidding, it’s actually going to happen. We’ll also find
out what makes his new companion so impossible and there’s a surprise that no
one has got right so far, and one that will change the course of Who
forever!"