What can audiences expect when they come to see Murder on the Orient Express on stage?

Bob: It's funny, it's exciting, it's adventurous, and it'll also make you think. When I did And Then There Were None people left going 'It's a lot to think about' or 'I need to talk about what happened and all of the characters'.

Michael: But hopefully if we get the pace right people won't be able to think fast enough during the show itself. It will be a night of intrigue with a great denouement.

How would you describe your characters' relationship?

Bob: Monsieur Bouc is the man who runs the train, he's very passionate about it and his best friend is Hercule Poirot, so he's very supportive towards him. Poirot is a genius and Bouc isn't, so he's often a sounding board and there's a little bit of Sherlock-Watson in it. Sometimes Bouc pushes back and he questions things, then at other times he just watches as Poirot weaves his magic and goes 'How extraordinary!' There is a great bond between the two of them.

Michael: There are some very interesting scenes going on around Poirot in which he just observes and I think he's quite a lonely person. To be on top of his game, to take care of his little grey cells, he has to distance himself from being too involved with people so that he can objectively see what their characteristics are, what their behaviours are and what they're up to, really. But yes, he and Monsieur Bouc are old friends and in fact we've made up a bit of a backstory for them, where they fought together in the First World War and Bouc saved Poirot's life after he was invalided out to England and ended up in Torquay as the type of Belgian refugee that Agatha Christie would have seen during her childhood there.

Michael, Poirot has been portrayed by many actors over the years. How are you making the character your own?

Michael: When you play a role it will naturally become your own but I carry the memory of everybody that I've watched play him. I don't try to compete with them and I like to acknowledge what they've done. I've really enjoyed all their performances but I think David Suchet in particular has dominated the national consciousness because he did it for about 20 years on television, so when people say 'Poirot' they automatically think of his appearance, his persona and his acting of the role. To veer far away from that would not be right but because it is a stage production there is more expression and more passion involved. We cannot be dependent on the television close-up, we have to project ourselves, and there is also room for losing your temper and getting exasperated, as well as being utterly charming.

You have a great rapport. Have you worked together before?

Bob: It's our third time. Previously we were in Hamlet together. The first time, he was Hamlet and I was Rosencrantz, then I was Horatio to his Hamlet. Both times it was blissful and the second time was a longer tour so we shared digs. What's lovely about it as well is that there is a sort of element of Hamlet-Horatio in the Poirot and Bouc relationship, and there are a lot of references to Hamlet in this play.

Michael: Ken Ludwig, who's adapted it, is a fantastic writer and he's also a passionate Shakespeare fan, so he's puts in quotes from Hamlet throughout the play. Then with Bob, it's very difficult not to enjoy working with him. He's big-hearted and I think he's the engine of the company as a result. It's a pleasure to be working with him again.

What do you think makes Christie such a revered storyteller?

Bob: She's the best at what she does. If you are in the mood for a murder mystery, she takes it to another level. It's not just that she's great at the narrative, telling the story and finding the gold within it, she's also very good at painting characters. She maybe isn't a Dickens but she's not far off in terms of the characters she creates. Also she's very good in terms of the psychology of people in extremis, so when people are pushed to the edge she's so accurate about human nature.

What do you think makes Murder on the Orient Express particularly compelling?

Michael: This is one of her all-time greats. Her writing is very dependable. You have a world created for you, which you can observe from the audience and still feel non-threatened by but yet you're intrigued by the terrible goings on in other people's lives, which is the function of theatre a lot of the time anyway. The engine of the play, the plot by Agatha Christie, is a very good one.

Are there still surprises for people who know whodunnit from the novel and previous adaptations?

Michael: There are, yes. The way it's staged, there are plenty of diversions and there are enough red herrings.

Bob: Our director Lucy Bailey has done a lot of Agatha Christies and she's got a real handle on it. She pushes the stories into unexpected areas and it's thrilling.

The play is set in the 1930s, so is it pure escapism or does it have themes that speak to contemporary audiences?

Michael: There is a small speech, without giving away too much, which relates the time of the 1930s to us now. The play is set in pre-Nazi Germany and it's on the doorstep of the characters' consciousness, even on the train. There's a certain sense of similar foreboding now for many people with the various flashpoints in the world.

Bob: With And Then There Were None it was very much British. This is more European, which is interesting because – and I'm not going to get too political – hopefully we've for the moment sorted ourselves out in this country. But things are very febrile in Europe.

What have been you career highlights on film and TV?

Michael: I enjoyed my little bit in Belfast with Kenneth Branagh just a couple of years ago and I enjoyed doing Henry V for Branagh as well, playing the Dauphin. I also enjoyed doing a TV series for Anthony Minghella called What If It's Raining on Channel 4, which was the precursor to the film Truly, Madly, Deeply, which was another enjoyable job.

Bob: I was in Holby City for 12 years, so that was a huge part of my life and I just loved doing it. I did an Ab Fab, which was exciting, and I really enjoyed doing Shakespeare in Love and learned a lot from that experience.

Does the Yvonne Arnaud have any significance for you?

Michael: I was brought up in Guildford for a couple of years so it was my local theatre and I look forward to returning.

Bob: It's a great theatre, close to home, with great audiences.

Murder on the Orient Express is at the Yvonne Arnaud from Tuesday 21 to Saturday 25 January.

Tuesday to Saturday evenings at 7.30pm, Wednesday, Thursday and Saturday matinees at 2.30pm.

Tickets from £39; concessions from £13. Book at https://www.yvonne-arnaud.co.uk/whats-on/murder-orient-express or call the box office on 01483 44 00 00.