It was a trailer for High School Musical that gave Ryan McHenry with his inspiration.
The Scottish director thinks the only way he enjoys the film is "if the whole cast is eaten by zombies".
This sparked the idea for the Anna film and Apocalypse which took place a public release in theaters on Friday – more than three years after 27 years from Dumfries died of cancer.
Director John McPhail took the project to bring it to the big screen.
"That's Ryan McHenry's idea," he said.
"Ryan wrote and directed a short film called Zombie Musical which later won the Scottish New Talent Bafta.
"Then it was picked up to be developed by Black Camel into a film."
However, Mr. McHenry – the person behind award winner Ryan Gosling will not eat the Cereal virus video – unable to complete the project.
"Through preparation and development, unfortunately Ryan was diagnosed with cancer and unfortunately died in 2015," said McPhail.
"His long-term friend and producer, Naysun Alae-Carew did not want the project to go away and wanted to keep such a memory so he started looking for a director.
"They saw horror directors and musical directors and unfortunately did not find the right one."
Then they saw Mr. McPhail's Where Do We Go From Here? – a romantic comedy home care set – at the Glasgow Film Festival, and that's when he got involved.
He said his last project was one that surprised the audience.
"This is a very fun and alluring film that gets some serious messages and serious tones – it's all about children who are dealing with death and this type of age," he said.
"People get a little behind their feet with it because they don't expect to finally cry.
"They are laughing, crying, and cheering, this is just a happy movie – this is amazing."
He said he had been "fascinated" by the response at the film festival and hoped it could have a broad appeal.
"This is not just a film for children or just for fans of horror or just for fans of music," he said.
"We want to make the film for everyone to go and enjoy and feel good and feel good and leave the cinema buzzing and excited."
Location of Scotland
The nomination for Scottish Bafta for the best feature film earlier this year was described by Mr McPhail as "extraordinary".
"This is a zombie music set on Christmas, it's crazy," he said.
The film is also proud of its roots and location in Scotland.
"The Glasgow Port is perfect for us and the people there are also brilliant," added Mr McPhail.
"We will go out in the wind and rain and snow – it doesn't matter if we are out there because that's what we got.
"That's what we shoot, that's our job."
That is something challenging, however, for actress Ella Hunt who took on Anna's role.
"Scotland is a great place to shoot and we have an incredible Scottish crew," he said.
"One of the biggest challenges is facing the cold because we filed in February 2017 so it's really very cold."
Even so, he said it was the role he wanted to secure from the start.
"I like the crazy concept – more courageous in some ways," he said.
"I really looked for the role of teenage girls who did not marginalize the teenage experience and that three dimensions.
"Anna has so many things at the same time that she is the most fantastic opportunity so actually I was shooting fast."
The music for this film was provided by Roddy Hart and Tommy Reilly who described this project as "really interesting" from the start.
"We have never written a musical before trying to get into a writing style like that is a completely new universe," said Mr Reilly.
He described it as "total music freedom".
"I think the thing we like most is that this is an ambitious project," Mr Hart added.
"This is a zombie musical that has a regulated comedy in Scotland, I mean what might be wrong?
"Every time we watch it, we find something new with it – this is a magic film."
& # 39; Really chuffed & # 39;
The finished film was devoted to Mr. McHenry – and the person who took on the role of director believed that he would like it.
"I can't film other people, I can't do other people's visions, I can only do it myself," McPhail said.
However, thanks to friends from Mr. McHenry who was involved in a film he believed had respected his memory.
"Only from their reaction, I know that he will be proud of it and really, also suffocated by it," he said.
"For someone who is really fun and a funny man and a sweet and sweet man, this is a real appreciation for him."