Here’s how we got on… Actor Dylan OBrien is on set, holding a machine gun in a darkened tunnel.

The ring of a bell and a shout of Rolling!

means filming has commenced and, right on cue, OBrien squeezes the trigger.

Youre literally watching a guy deal with an aftermath of this dramatic phase of his life.

It completely changes him.

This is what we do.

He wants to right something that happened to him.

In person, OBrien comes across as refreshingly down-to-earth and thoughtful.

The word is that Clintons well ahead, but theres still that lingering fear that Trump might actually win.

Its a simplistic solution, but its also partly wish-fulfilment, di Bonaventura says.

Dont we wish [terrorism] would just go away?

Yeah, I do.

It was weird, when we were picking locations, that we think about security.

Thats weird, you know?

Not many years ago, we shot in Egypt, and we hardly thought about it.

I mean, we thought about it, but today you wouldnt even consider it.

The prism of our decision-making has completely changed we hired security firms to do an analysis of London.

Whats the risk of filming in London?

Thats a different world.

Later, Im taken to an edit bay where the footage captured so far is being carefully assembled.

The hardware theyre using simulates the pain of a gunshot somehow.

They nod at this, seemingly satisfied, or maybe just being polite.

I get a similar sensation from the bathroom scene; is it too much?

Will they lose the audience with this?

She has that vulnerability but you dont see it 95 percent of the time.

Thats interesting to play.

There are certain small moments she has with Mitch.

It toughens you up, which is why she comes across as very strong.

Its second nature to her.

Itll be interesting to see what the politics of this movie are like.