"When Professor Dumbledore from Harry Potter likes the story, you know you're in business."
It is the big-screen release Wales' football fans have been waiting for - the movie that transforms Gareth Bale and his Wales Euro 2016 teammates from sports stars to film stars.
But when film icon Sir Michael Gambon likes the sounds of "Don't Take Me Home" so much that he fancies dropping by this week's London premiere then you realise the sporting storyline is a little special.
"When you hear a movie legend like that, likes the story then you know you've got a storyline that has a wide appeal beyond Welsh football," said director Jonny Owen.
Don't Take Me Home, named after Wales football fans' Euro 2016 terrace anthem, premieres fittingly on St David's Day.
But like Wales' down-to-earth players, the official premiere is far from the glitz and glamour of Leicester Square but more an industrial park outside of Pontypridd.
But in the week that Leicester City's fall from Premier League grace finally unravelled with the sacking of their manager, you might be forgiven for thinking this is just an overindulgence about just another sporting fairytale.
This starts with the most tragic of beginnings - the death of Wales football manager Gary Speed.
A group of young players, most of whom were friends after growing up together in Welsh youth teams, had to deal with the grief of not just losing their boss but their role model.
In that context, what they achieved less than five years later - qualifying for Wales' first major championship finals in almost 60 years - seems "worthy of immortalising in film".
It was certainly beyond the wildest fantasies of any Welsh football fan - especially when they were below Haiti and Guatemala at 117 in the world rankings in 2011.
Then in November of the same year, Speed was found hanged in his garage, aged just 42.
It did not just resonate in Wales and football, Speed's death shocked the country.
"Wales were constantly suffering so-called heartache, failing to qualify for tournaments at the final hurdle, but Gary's tragic death put those disappointments into perspective," said Owen.
"Gary's death was obviously devastating for his family and friends, but the sadness and grief must have affected this group of young lads who were loving playing football for one of their Welsh footballing heroes.
"It seemed to have a profound affect on them. It seemed to galvanise an already pretty strong bond, a togetherness and also context - as if they could come through this, then playing football and dealing with that pressure would be easier.
"No-one could have predicted then that virtually the same team would create history at Euro 2016 - those boys have some character."
The rise to the European Championships was Roy of the Rovers stuff.
Built on a foundation of structured defending with the added sprinkle of stardust from the world's most expensive player, Wales defied the odds and not just qualified for their first finals since the 1958 World Cup - they reached the semi-finals.
No other team in history has risen up Fifa's world rankings quicker than Wales. From 117 to eighth in four years.
But that meant nothing without qualification for a finals. Wales had promised qualification a dozen times before, only to come up short.
But Chris Coleman's team became one of the smallest nations to qualify for a major tournament - and they even did it with a game to spare.
Everywhere you looked in the Wales team, there were personal battles to overcome.
Aaron Ramsey, the player who battled back from a double leg break in 2010, was singled-out by many as the player of the tournament.
While Hal Robson-Kanu, whose sensational goal in the quarter-final win over Belgium will go down as one of the greatest strikes in any tournament, did not even have a club.
So it was no surprise Wales took the Euros by storm with a chilled-out and friendly approach that turned them into everyone's favourite second team.
From Joe Ledley's dancing and Bale winding-up England to the squad cheering England's exit on social media and Chris Gunter's "chin-up" message to Welsh fans - this was a team at one with itself.
"The rapport the team had with the fans made the Euros extra special for me," said Owen, a director once described by the Guardian as football's greatest film-maker.
"It was like 'we've waited almost 60 years for this so let's enjoy it'."
"It was one the most memorable of summer for the Welsh - and everyone was getting involved - from Cerys Matthews, Michael Sheen, Ioan Gruffudd to the Manics and the Prince of Wales.
"It was more than just a football tournament for us, it was more of a cultural event that every Welsh man or woman wanted to be a part of," Owen said.
"It was a very special time - I just hope the film does it justice."
The Welsh public has certainly responded as once the film goes on general release this Friday, there are 80,000 possible cinemas seats across Wales and the UK.
"Ticket sales have been phenomenal," added Owen.
"We put 10,000 seats on sale initially and they went. So 80,000 are now on sale which is the amount of fans that went to France last summer.
"To put it into perspective, if 40,000 turn up then it flies into [the] top 10 in the box office - that would be crazy."
The latest film royalty to show an in interest in attending the Don't Take Me Home premiere is Hollywood actor Woody Harrelson - star of 1992 cult movie White Men Can't Jump.
Ironic really as Wales could have done with Harrelson when Cristiano Ronaldo out-jumped the Welsh defence in that semi-final defeat to Portugal.