Agatha Christie's classic thriller of diminishing numbers - Brighton date

He is Dr Armstrong in the show which plays Theatre Royal Brighton from January 9-13; the Yvonne Arnaud Theatre, Guildford from January 16-20; and the Mayflower Theatre, Southampton from April 8-13. Famously it’s the tale of ten strangers who are lured to a solitary mansion off the coast of Devon. When a storm cuts them off from the mainland, the true reason for their presence on the island becomes horribly clear – and Bob is loving it.

“I think what Agatha Christie does so brilliantly is twofold. If she were just a brilliant writer of thrillers and stories around murder and death then she would not be nearly as successful as she is. But I think she has got the great gift for knowing how humanity works when it is put in extreme circumstances, particularly to do with when we cross the line into murder, into doing things that we really should not do. And when it comes to that, I think she is as good as anybody we have ever had. And if she didn't have that dimension to her writing then I just don't think we would believe the stories in the way we do.

“We were discussing in rehearsals the fact that there is always a point at which Agatha Christie stretches our credulity very far and there is a point in this where the murders happen one after another very quickly, where she really pushes the envelope. But the fact is that she gets away with it because the way she describes it and presents it completely rings true. Every character rings true. And maybe there is a third thing. She has that great English gift of writing character. She writes the most extraordinary characters. Everybody knows Poirot. Everybody knows Miss Marple and the fact is that all these characters are properly 3D characters. It is like all the great stories. When you think of Pride And Prejudice or things like The Importance Of Being Earnest, the reason that they are so perfect is that everything works completely about them.”

As Bob points out, copying is a sign that something works, and if you take two massive films, two of the greatest films of their genre, The Thing and Alien, the fact is that both of them are “basically ripping off And Then There Were None.” As for the plot, it turns out that all these people are on the island for a reason: “And the reason is that they have done something. They have been brought together because they have committed murder… and that comes out very quickly and that's what sets it up. That's the beauty of it. It is very rare to have a play in which everyone is flawed, in which no one is a very nice person. There are no great sympathetic characters. There's no one for the audience to latch onto. The other great beauty the play is that the audience are effectively rudderless. There is no Poirot. There is no Miss Marple. The audience have to solve the mystery for themselves.”