Image source, Alex Bailey/Focus Features/StudioCanal Image caption, Andrew Scott plays chief meteorological adviser James Stagg, who advised General Eisenhower during World War Two
Andrew Scott says he loved the challenge of his latest acting role in the film Pressure, as the meteorologist key to the success of World War Two's D-Day - the largest seaborne invasion in history.
“Group Captain James Stagg may not have been the most charming person, but I think he had a huge amount of humility in the face of nature. And that's one of the themes I think of the film," Scott tells the BBC.
"He appeared to me to be an extraordinarily interesting cinematic character, as well as an unsung hero from history."
Stagg played a crucial advisory role when US General Dwight D Eisenhower invaded Normandy, laying the foundations for the Allied victory in World War Two.
"It was a wonderful part to play," he says, while painting a mixed picture of Stagg, calling him "very chilly", while also "forthright, direct, obsessed with weather - and not afraid to speak truth to power".
Image source, Met Office National Meteorological Library & Archive Image caption, James Stagg was from Dalkeith, near Edinburgh
Stagg isn't a traditional war hero, something Scott clearly relished sinking his acting teeth into.
"I really enjoyed the way that Stagg was not interested in ingratiating himself with anybody," he told BBC Culture correspondent David Sillito, calling him "a real fish out of water in this situation".
The actor's other starring roles couldn't be more different, including romantic fantasy film All of Us Strangers, for which he was nominated for a Golden Globe, plus his memorable "hot priest" in TV's Fleabag and the menacing Jim Moriarty in Sherlock, for which he won a Bafta. His award-winning stage roles include Vanya and Present Laughter.
In Pressure, Stagg is thrown into a high-stakes furnace of egos. He has to work with a team of meteorologists who robustly and publicly disagree with each other.
Stagg "wasn't a particularly garrulous character" Scott says, which is partly why he was perhaps an unlikely hero.
"So many of the heroes in our own lives don't have that big swashbuckling moment," he says.
"And you know, a hero comes in all different shapes and sizes.
"I tried not to be afraid of the fact that perhaps, at the beginning, the audience might be like, 'Who is this guy?' And hopefully by the end we understand his motivations and his inner workings."
Image source, Alex Bailey/StudioCanal SAS Image caption, Brendan Fraser (far left) plays General Eisenhower, who led the Allied forces and went on to become US president
The actor is speaking to the BBC on board HMS Belfast, which led the opening bombardment for the D-Day landings , when tens of thousands of troops from the UK, the US, Canada and France attacked German forces on the coast of northern France on 6 June 1944.
Eisenhower needed a full moon, low tide, not much cloud or wind and low seas , external .
"The stakes were so enormously high... they were all locked down, and they couldn't leave the place. Stagg's wife was very heavily pregnant at the time, so it was a very, very difficult time for him," Scott explains.
"It's completely unimaginable, the pressure that they would have been under, not just Stagg, but everybody in the building."
This of course explains the name of the film, which is based on the successful 20…