It's learning from day to day, at the interval myself and Ian walk up the steps together to our dressing rooms and he says "what about that moment" and I say "what did you think about my moment", we're constantly discussing it and constantly trying to find new and exciting ways to tell this story in the way that Harold probably wanted it to be told.

there was a moment when, on the first day of the rehearsals, when Sean was stood at the front of the room and everyone was looking down at the model of the set and he started to introduce people, and he said "most of us have worked together before, except for Damien" [laughs] so I was like 'play it cool, play it cool' .. but that was so exciting because I didn't expect anything from anyone and it was a blank slate for me going in ...

I must have come through that door a hundred and fifty different ways and Sean would say, "that works, that doesn't work, that's rubbish, don't ever do that again, that's really good, let's explore that further" it was just a constantly evolving thing. I think I came on stage different on press night than I ever came on stage before, so suddenly Ian was a lot more shocked as an actor and as a character, so it feeds into that. Ian said a great thing as well, if you surprise yourself then you'll surprise the audience and you'll surprise everyone on stage, and that's what people are looking for, to be surprised. After six months of filming I started having dreams about going back on stage and that's when I know it's time, not time to go back but time to hopefully get an audition for a job [laughs].

It's exhilarating because it's so exposing, that first day of rehearsals.. there's an element of "ok, you've been cast, what've you got?" And you're nervous to get up on your feet, and I was so nervous.. it was day one week two, and it was me and Ian in the room together with Sean the director and on Sunday night I was like 'I'm going to be in the rehearsal room with Ian McKellen tomorrow, I need to bring my A game'. So I sorted my living room out into a mock of the set and I must have done ten different versions of how I might do it, just to settle my nerves, and once I had that behind me, then I knew that I could try those ten things tomorrow, if they didn't work I could try ten more ways.

I feel like this character has evolved so much in my head and it's changed the way I look at certain things you know, because he's a cocky f***er, and I'm not really.