In a way, the atmosphere of the series is similar to The Americans’ — themes of trust, betrayal and paranoia permeate both. In the BBC2 series, based on Eugene McCabe’s book of the same name, Catholic and Protestant divisions have the power to turn families and neighbours against one another.
Rhys plays Billy Winters, a Protestant landowner whose Catholic wife died in a tragic accident, leaving him to raise his step-daughter, Beth (Ann Skelly), whom Billy has developed confused feelings for.
“The turn was a complete 180, really,” Rhys says of the role.
Set during “the start of modern terrorism, terrorism as we know it,” according to the show’s creator Allan Cubitt, secrets are a key commodity in Death and Nightingales, and during the series Billy plays his part in gathering information.
Perhaps, RadioTimes.com suggests, it wasn’t such a great leap to go from playing a Soviet spy to… “a spy in Northern Ireland!,” Rhys finishes, laughing. “Or a possible spy.
“Yeah, maybe not [that great a jump], although just the emotional turn I meant. And Billy isn’t a spy. But it is kind of, maybe the sadness is that it’s an enormous part of our human make-up as to, that’s what we do.”
Billy, is in a “kind of love triangle” with Beth and the charming Liam Ward, played by Fifty Shades of Grey star Jamie Dornan. He could, on first glance, be a two-dimensional monster, but in Rhys’ hands the role is much more human, even sympathetic.
“I just thought, if he’s a monster, this sort of seedy, pseudo-molester, you kind of go, well, you write him off. There’s no interest,” he says.
Rhys, who is Welsh, had to learn a Northern Irish accent for the part – a task he’d originally envisaged would be much easier than his take on American.
“I arrogantly thought with the kind of generic American, I find there are less extreme sounds to hook into, and with Belfast, I thought, this will be great [as] the accent is very strong,” he explains. “But then… I was like, ‘Oh no, this is gymnastically harder than I thought.”
Following on from Death and Nightingales, Rhys has also just wrapped filming in Pittsburgh, where he shot a new film biopic, Mr Rogers, alongside the legendary Tom Hanks.
On working with the two-time Oscar winner, Rhys says: “It’s everything you want, and it’s terrifying… [He’s] an absolute boyhood hero. So when I was in front of him, I was really dumb struck with nerves.
“It was only in the third week that I started relaxing a bit… I’m sure he spent the first two weeks going, ‘What’s wrong with Welshie?’”
Rhys, who was born in Cardiff, Wales, is also keen to bring some Welsh legends to the small screen.
“Owain Glyndwr [is the dream part]. It’s like the Welsh Braveheart basically. He was the reluctant hero… I think it’s an incredible story. We call it the real Game of Thrones — it’s like Braveheart on steroids, really.”
TV execs, you heard it here first.
Death and Nightingales first airs on BBC2 on Wednesday 28th November at 9pm