Knock Knock, a haunted house story with a sci-fi twist, was a highlight ofDoctor Whoseries ten.

Was it the first pitch you made toDoctor Who?

They got whiff that I was aDoctor Whofan and called me up, which I was very pleased about.

Id only written television for a few years before that happened, I hadnt written a huge amount.

How did your story evolve with Moffat?

Its a writing masterclass spending any time in a room with Steven Moffat and his brain.

I know other people have said that but its a really distinct phenomenon.

His brain jumps to the correct or more interesting solution about ten times more quickly than us mortals do.

I learned so much from it.

What would be more surprising thanthat?

It feels really collaborative and fun knocking ideas about with another person who writes six episodes a series himself.

ItsDoctor Who, so how could it be better?

They were sadly and tragically from me, yes, [laughs].

There were probably more of them, originally.

You had fun with that then?

its more just what I do anyway, you know good writers borrow, great writers steal!

It also makes sense because thats the same person.

Your episode also seeded in Twelves Regeneration.

He gets the big takeaway at the end and you also had the mystery of the vault to handle.

How did you go about threading that stuff in?

Were there guidelines as to what you could and couldnt reveal at that point?

The vault stuff at the endIm sure Im allowed to say thisis Stevens, not me.

Steven Moffat wrote that scene at the end.

you could see it here], if everyone wants to go out and buy that!

In it, theyre back in the house and it sort of rounds the episode off.

and he moves on very quickly.

I think some of the other writers had to put Nardole in their episodes when he perhaps wasnt originally.

I think I judged it pretty well.

I think I seemed like a reasonable grown-up before I got into that.

I was exactly the same, making sure I didnt gush all over him about King Charles III.

I think we both sat there in silence.

I had no idea that he was aDoctor Whofan, but I loved his episode.

His episode was great!

I particularly loved the episode where I was dressed up as Razor.

That was fun to do, to look completely different.

It was great fun and a real honour as well to be able to work with Peter.

Ive been through two Doctors in my time, and not a lot of people can say that!

Both terrific actors as well.]

Yeah, Id love to.

Isnt it a brilliant show?

What other show can entirely reboot itself in its very DNA and change everything about itself?

Isnt Jodie brilliant already?

What a clever man and what clever choices hes making, brilliant.

Trauma starts on ITV at 9pm on Monday the 12thof February.