It's a brave man who attempts to fill Colin Firth's shoes, although Matthew Rhys doesn't exactly sound fearless. "It's terrifying. I hadn't realised the reaction would be so strong. My dad said, 'Are you playing Colin Firth?'" He isn't - but he is pulling on Firth's billowing white shirt to portray Mr Darcy in Death Comes to Pemberley - PD James's detective fiction picking up six years after Pride and Prejudice left off.
Arguably Firth's best known scene in his 1997 depiction of Austen's brooding hero involved a lake and a clinging white shirt... "The best thing about it is that shirt," announces Rhys, beaming. "We were discussing whether it's chicken or egg syndrome: whether women had this thing for the billowing white shirt before Colin did that or whether it came after? We don't wear the big coats down to the set - we just wear the white shirts and I swear to god it has an effect. They don't get faint or anything, but they look at the shirt and go, 'Oh, so what are you filming?'"
Does Rhys get his own 'lake scene' in Pemberley? "There was a moment at Chatsworth and everyone was going, 'do it, do it,' but I had a microphone pack on. I would have done. I have a horse moment. Matthew Macfadyen had the billowing coat mist moment - I have the horse billowing coat mist moment."
Although Death Comes to Pemberley sees a dark veil pulled over Austen's world of tight-laced social politics as her villainous Mr Wickham finds himself the prime suspect in a murder trial following the unexplained death of his travelling companion. The reappearance of Darcy and Elizabeth's old foe causes ructions within the household, driving a wedge between our favourite literary couple. "Darcy panics and withdraws and can't really deal with it. It's too much. If he loses his reputation, his credit goes and people die - if they lose their livelihood they're dead so it's an enormous pressure on him which might not be understood by a modern audience."
Despite being adored by millions, it wasn't a book Rhys held in a great deal of affection during his younger years. "I'd read Pride and Prejudice as a teenager. We had to in school and I hated it. To a 16-year-old it's just rubbish, but then I read it again. She had something, Austen. That incredible insight into humanity coupled with this incredible eloquence."
She also created one of our best-loved romantic heroes - the fantasy of women across the globe. "The 'Darcy effect'." explains Rhys. "It's like the shirt effect. You say Darcy and it conjures up an image which some women don't necessarily have a detailed relationship with but it's become a romantic notion."
Not all women, as Rhys admits his Americans co-star Keri Russell - who herself is the star of this year's Austenland - "laughed uproariously" at the news of his casting. "For too long and a little bit too sincerely."
After a regular role in Brothers and Sisters until 2011, The Americans saw Rhys's star soar yet again and with a critically-acclaimed first series in the bag and a second season in production, the Welsh actor has succeeded in following fellow Brits Hugh Laurie and Damian Lewis to leading roles across the pond.
But despite now spending six months of the year filming in the States, Rhys has a great deal of affection for his home turf. "Doing this job, I've realised how much I miss British actors - the absolute banter, I've laughed so much.
"Me and Matthew Goode [who plays Wickham] were also discussing the physical geography and topography in places. And I know it's a cliché but I do miss fish and chips, the humour, pubs..."
He'll get his fill of all the above when he returns to his native Wales to spend Christmas with his family. "It's a very set in stone tradition. Christmas Eve I go out with my school friends and argue with mum about how much I'm allowed to drink so I don't ruin Christmas Day. Christmas Day: chapel, lunch, presents, argument, Bond film, bed. Booze and turkey."
Will Death Comes to Pemberley make an appearance in the schedule? "I won't be watching it with my family because the sledging will be too heavy - "Nice hat","God you sound Welsh", "Look at the way he walks"...
Death Comes to Pemberley begins on Boxing Day at 8:15pm on BBC1