The acclaimed Irish performer talks about the call from Hollywood that every actor dreams about

Let's start with True Blood ...

We're going to end with True Blood, too, aren't we?

Er, no. Anyway, you're a witch ... It's not exactly typecasting.

No. I just got a phone call one day. They didn't even go through my agent. Hollywood ringing – it's what everyone dreams about. They'd seen me in Medea (1) and decided I'd be ideal. Medea was very glamorous, though; Marnie isn't, but I wanted to do something that was so far away from what I was used to. I did a lot of research by going to witches' meetings …

How do you find a witches' meeting? Is there a Witches' Anonymous?

There's the Bodhi Tree book store (2)in Hollywood, which has books on healing and that sort of thing, and in the window there are notices for a phenomenal range of offerings. I went to one meeting to bring back the dead.

Did any dead people come back from the dead?

Well ... They do. But not in the form of True Blood. They come back vocally.

You believe that?

I didn't say that! But it would be rude of me to be unpleasant about people who let me observe their meetings. So let's say I saw them talk to the dead. At one meeting, a woman apologised for not being able to make contact with the dead. I said not to worry as I'm having trouble contacting the living.

How do you say a line like "Great Minerva, take us from our realm to yours" with a straight face?

It was a challenge.

Was appearing in Harry Potter useful training?

No. I was Petunia Dursley, a muggle, in those films.

Didn't you get any tips from the others?

No, they kept us all apart. They filmed witches work on one day and muggle scenes on the other.

Would you have taken this role 10 years ago?

I've never taken myself too seriously, but it's true that big TV shows like this have become more acceptable. HBO has become the hedge fund of classical acting. The writing is excellent and they aren't afraid to use the full potential of wide-screen TV. It was like being invited to appear in 12 movies. It's by far the biggest thing I've ever done: it gets an audience of 30m in the US. I get mobbed walking down Fifth Avenue. That's never happened to me before.

Are you keen to do more vampire roles?

Not particularly! But True Blood is a critique of the way the US treats minorities. Now that the vampires have conformed and no longer drink human blood they get equal rights and the vote.

Is it true friends call you Fifi?

Very few people get to call me Fifi. And even fewer get to call me Feef.

Can you still recite The Waste Land (3)

Of course. It doesn't leave me. The words are like a movie that I see in my head. I can also remember most of As You Like It and Much Ado, which I performed in my 20s. The plays you learn when you are young tend to stay.

How do you learn your lines?

The key words are learning by heart, not learning by head. When you're on stage, it doesn't feel like memory, it feels like the present. I don't have to rummage through mental files to find then. Plays like Beckett's Happy Days (4) are the trickiest. The dialogue is much, much more fragmented and exists only in rhythm.

Have you ever lost your place in a play and had to ad-lib?

Ah, there's your stupid question! I was waiting for it to come. The answer is no ... A play is not an act of running lines. If it feels that way to you as an audience, then you ought to leave and go have dinner. If an actor is distracted and forgets his lines, it means the play is under-rehearsed. A play is about the concentration of the moment: you can't say anything else but what you say. There is an inevitability about it.

Who is the best person you've ever worked with?

Are you mad?

So my shrink says.

I've got to live in the world, so I've no intention of answering that question. I'd end up alienating almost everyone else I have ever worked with.

Alain de Botton is planning on building a temple of atheism. Would you worship there?

I find atheism as ludicrous a notion as theism, though a world with theism strikes me as a more imaginative one. True or not, the imagination of religion is useful to being human. I don't believe in God, but I can't not believe in a world where God exists.

You once played Richard II (5). Are there other male roles you would play?

I've no desire to play any more men. Richard II was an odd man – more like a girl – so it seemed a valid experiment. The job of the theatre is to excite the imagination, not to reinforce history.

Is there one character you identify with?

Hedda Gabler. She lives primarily in drawing rooms and we all live in drawing rooms. She also constantly doubts her courage: when I feel frightened about something, I think of her.

Foot notes

(1) Fiona Shaw appeared in Medea by Euripides in 2001 (2) The Bodhi Street book store closed on 31 December 2011. It is currently awaiting reincarnation (3) Shaw first performed TS Eliot's The Waste Land as a one-person show in New York in 1996 (4) Shaw appeared in Samuel Beckett's Happy Days at the National Theatre in 2001 (5) Shaw played the title role in Shakespeare's Richard II in 1995 in a production directed by Deborah Warner



• True Blood is on FX on Sundays at 10pm