We know him best as the charismatic Dr Max Gallagher from BBC’s Casualty, but Robert Gwilym is playing a very different and more sinister role when he arrives at Chelmsford City Theatre as part of a UK National Tour.

The Business of Murder is a slick stage thriller by Richard Harris, whose other writing credits include The Avengers, A Touch of Frost and The Sweeney.

The play follows the story of a dour man named Stone (Robert Gwilym), who invites television playwright Dee (played by Joanna Higson) over to his flat on the premise of discussing a script. Once there, she is surprised when Superintendent Hallett (Paul Opacic) also arrives for an entirely different reason.

We caught up with Robert to talk about his latest acting role.

Describe the character you are playing.

Stone is a very prissy little man who certainly likes his brown clothes! He’s a cardie-wearer who is portrayed at first as a tidy little man in his flat, yet it soon transpires that this initial appearance is not entirely genuine. He does in fact harbour a few grudges.

What attracted you to the role?

The character of Stone is a fantastic role to play. It offers tons of opportunities; his personality changes as the play develops, which for me incorporates a lot of fun, and a lot of anger and spite which makes him a very interesting, multifaceted character to play. And, of course, it’s a very exciting story!

Are there any similarities between yourself and Stone?

I hope not... But I suppose I am quite tidy which is a trait we have in common. But with regard to sympathising with Stone’s character, no I’m afraid I don’t. He is extremely self-centred, self-pitying, and not at all how I would like to be perceived out of character.

The Business of Murder is on at Chelmsford City Theatre, Fairfield Road, Chelmsford, CM1 1JG, April 21 to 25. Details: 01245 606505, chelmsford.gov.uk/event-type/theatre