The 53-year-old actor – known to Downton fans as bumbling servant Joseph Molesley in Downton – stars as a military doctor in charge of the field hospital in the BBC1 drama.
“It’s nice to have people saluting me for a change! I usually play either servants or serial killers, so to have a character with a quiet authority about him is strange. It’s taken me a while to get used to it.”
And despite starring in global hit Downton Abbey, Kevin claims he’s hardly ever recognised in public – except when someone recognises him from playing a murderer.
He revealed: “There’s a level of recognition, just because of the number of people who watch Downton, but they don’t shout at me in the street.
“I played a killer in Jimmy McGovern’s The Lakes a few years ago and somebody screamed at me on the Tube, so I was worried that I’d have to get used to that with Downton.
“But normally it’s just double takes and people asking if I’m the man who did their central heating last year!”
The Crimson Field, BBC1, Sunday