Dallas star Patrick Duffy heads to the Guildford stage for twisty thriller

It plays Guildford’s Yvonne Arnaud Theatre from June 14-18.

Inspector Levine is called to a house in the remote Catskill mountains to investigate the disappearance of newly married Elizabeth Corban. But when Elizabeth suddenly turns up, her husband seems surprised – and this is only the beginning of a truly baffling train of events, in which nothing is what it seems and no one is as they appear…

Gray said: “I didn't know it at all but I had worked with Bill Kenwright about 20 years ago on Anthony Shaffer's Sleuth which was a big hit. Sleuth was a two-hander and it was a great success and we ran in town for a long time. But the point of that thriller was that you think you can guess and then at the end when it's revealed, the audience just goes ‘Oh!’ You get that intake of breath from 500 people and it's a fantastic feeling on the stage, and you get that in this show too.

“The show is a bit misogynistic and is very much of its time in the way that women are treated, called honey and all that sort of thing and some of the lines I dread saying sometimes but you've just got to bite the bullet and know that this is where it's going to land in the service of the play.

"I'm not excusing it at all but you can't change it. You've got to keep it how it was. It is not a play you can update. You've got to do it as a period piece set in the 1960s.

"But it is great fun to do and it is very funny.

“It is a silly set-up but it's also a very clever set-up and you can watch the audience think that they have worked it all out when you get to around three-quarters of the way through and you can sense them going ‘Yeah, yeah, yeah, we've got it!’ but then haven’t, and then of course at the actual denouement again it's ‘Oh!’

“And working with Patrick Duffy is great. He's a wonderful guy. He's got such a lovely feeling for the dialogue. It is almost like a jazz piece.

"We don't improvise at all. We absolutely keep to the script but we do improvise the pace and the tone and sometimes it really bubbles and sometimes it really crackles and sometimes we would just give each other a little squeeze on the shoulder because it is all going so well and just feeling so buzzy.

"But at the same time it's a very wordy play.

"We had a week off and so we had what we call a speed run where we just go right through it very very fast in the theatre bar or in the dressing room and after a week off you think you're going to forget things and then you just realise how wordy the play is. There is so much to say and obviously I am doing an American accent with two Americans which is a real test and they're not going to let me get anything wrong!”