The true story of Manchester United's famous 'Busby Babes' and the 1958 plane crash in Munich that claimed eight of their lives is recreated in new BBC film United.
We report from the set of the TV drama, in which Dougray Scott appears as manager Matt Busby and David Tennant plays coach Jimmy Murphy.
On a park in east London, a group of young men are spending a very chilly Monday morning playing football.
It might be any friendly kickabout, were it not for the heavy leather ball, their old-fashioned kits and the cameras filming them do it.
"The ball is not yours, it's the team's!" exhorts a tall onlooker in a blue tracksuit. "The ball is round to go around!"
The accent might sound Welsh but the features are unmistakably Gallifreyan, belonging as they do to former Doctor Who star David Tennant.
On the touchline stands another figure in a grey Trilby and tan overcoat. On closer inspection, he is revealed to be the Scottish actor Dougray Scott.
For the purposes of today, though, he is Matt Busby - the legendary Manchester United manager who will be forever synonymous with the players who perished in the Munich air disaster of February 1958.
At the time of the accident his team were on their way home from a European Cup match against Red Star Belgrade.
After a stop-off in Munich to refuel, the Ambassador prop-plane skidded off the runway on its third attempt to get airborne for the onward flight.
The crash, which resulted in 23 fatalities, remains the most tragic and emotive episode in the club's history.
Small wonder, then, that the makers of United insist they took pains to depict the event both tactfully and sensitively in their 90-minute drama.
"We've made every endeavour to be as accurate and truthful as possible in spirit and intention," says director James Strong.
"We want this to be a fitting and appropriate memory of these amazing players, this amazing team and this amazing story that a lot of people are aware of."
"It's a fascinating period of Manchester United's history and a fascinating period of football in general," Scott agrees.
"It's an interesting and important story. The film-makers want to pay homage to that and be respectful to all the people involved."
Among those people is Bobby Charlton, who walked away from a disaster in which seven of his team-mates died.
United staff, sports journalists and crew members were also killed. An eighth player, Duncan Edwards, survived the crash but died in hospital later.
United stops just short of recreating the crash, limiting itself to dramatising events immediately preceding and following it.
Yet its scenes of burning debris, dead bodies and wounded victims makes it a harrowing watch every Manchester United fan is sure to have an opinion about.
The drama goes on to show Murphy, who was not involved in the accident, rebuilding the decimated team as Busby recovers from his injuries and Charlton grapples with his grief.
For all the tragedy, though, United is not without humour, scenes in which alcohol is swigged before matches and pipes are puffed in the changing room offering a light-hearted commentary on how the beautiful game has changed over the years.
"On a very basic level it's a true story," says Tennant. "But it also looks at the arbitrary nature of fate, the capriciousness of life and the triumph of the human spirit.
"It's extraordinary that the story hasn't been dramatised before. There's never been a straightforward film or TV drama about this extraordinary dramatic story and it's long overdue."
Most of United was shot before Christmas in and around the North East of England. Because of heavy snow, though, Strong was unable to get footage of his players actually playing.
"Unfortunately we picked the worst winter in living memory so we didn't manage to shoot any football stuff," he explains. "There was literally snow on every single pitch."
"It's a bit tricky when you're making a film about football which, inevitably, has to be shot outside now and again," says Tennant.
"There were a few scenes that had to hang over so we could find a patch of grass to shoot them on."
The scenes in question feature in a training montage that shows Murphy putting his charges through their paces.
The footage is also included in a cinema newsreel about Busby's fresh-faced team shown prior to their European trip - the calm before a storm that to some is as raw today as it was more than five decades ago.
Yet if there is any pressure on Scott's shoulders, the 45-year-old is wearing it well as we take refuge from the cold in his well-heated trailer.
"The only responsibility I feel is to portray Matt Busby as truthfully as possible with all the tools I have available to me," he says in his low Scottish burr.
"I'm not the writer; I'm just an actor. My job as an actor is to try and bring this character to life."
United can be seen on BBC Two on Sunday 24 April at 2100 BST.