Harry Reid has been saying his "Witness For the Prosecution" lines in his sleep.
The former "EastEnders" star recently landed the role as Leonard Vole in the theatre production, and he is so used to learning multiple scripts from his time as Ben Mitchell in the BBC One soap, he has been sleep talking his words after taking on the "very different" project.
He exclusively told BANG Showbiz: "One thing that is a skill you learn at "EastEnders" is keeping up to where you are in your story, because we don't shoot chronologically.
"The directors are very good at that, they have your journey as a character and they'll help you because you're trying to keep up with so much stuff.
"But in this it's one play that I'm doing over and over, and I do the lines in my sleep now. I think I actually say them in my sleep.
"It is very different. For that aspect it is nice to keep on one constant journey with this character. I can just keep living that journey over and over and finding new bits in it.
"But it was never a problem keeping up with the story at "EastEnders"."
But after becoming "comfortable" with the script for the Agatha Christie play - which also features "Darling Buds of May" actor Philip Franks - he has enjoyed having a bit more artistic licence with the part than he had at "EastEnders".
He added: "It's a very different skill at "EastEnders" because you're doing it page to page, you can fine tune it, whereas here we do that in the rehearsal process.
"We had three weeks of rehearsals, which was very small compared to most theatre shows. It's a credit to everyone on this show. I have to pat myself on the back and everyone else because we've done well.
"So we did the work you do at "EastEnders" during the take in the rehearsal process.
"We're now into our second week and we're comfortable with the dialogue. That's the big thing, once you're comfortable with that you can add in movements. Not lines but we can add in little elements and change the pitching of the lines. But the two projects are very, very different."
"Witness for the Prosecution" runs at London County Hall.