Rachel Morton, (14), Myles Thompson, (11), and 13-year-old Eoin McAndrew, who take drama classes at the Pamela Cassells School of Performance in Portadown Town Hall, all have parts in the film adaptation of the popular children's book, 'City of Ember' by Jeanne duPrau.
The movie, made by production company Playtone which is co-owned by Tom Hanks and Walden Media, was filmed in the Titantic Quarter in Belfast last year.
The trio spent a week filming their scenes in a former paint hall which was transformed into a post-apocalyptic city for the film last June, and they rubbed shoulders with some of the movie's stars including Bill Murray and young Oscar-nominated actress, Saoirse Ronan.
The budding young actors, who are friends, had to adopt American accents to play students in a scene shared with the Mayor of Ember, played by Murray.
The movie is expected to be a box office smash when it is released on Friday, October 10, and Rachel, who lives in Bleary, said she received tickets to attend the premiere in Belfast next Thursday.
"I'm so excited and I just can't wait. I made so many friends on the set during filming and it'll be great to see them all again," she said.
Speaking to the Portadown Times while filming a Northern Ireland movie entitled 'The Race' in Co. Mayo, Eoin said he was "thrilled" to have acted in a major Hollywood movie. "The film sets were just fantastic and everything just looked so authentic. I'm taking my family to the premiere but I'm organising a big trip to the cinema with my friends to see the movie," he said.
But it was the off-screen antics of Murray that provided some of their memorable moments of filming for the trio. "In between takes there was a lot of time to kill on set and Bill Murray was just lovely. He talked to everybody and was just laughing and joking. He even sat on my and Eoin's knees!" laughed Rachel.
Myles, who has since acted in children's television series 'Emu' with Toby Hull, the son of the late Rod Hull, for ITV, said filming 'City of Ember' was an "experience" he would remember for rest of his life. "It was just an amazing opportunity. Everyone was great to work with and I was never once bored. I'll never forget it," said the Wallace High School pupil.
He added that he was also impressed by the film's special effects. "There's some great stunts and the sets were amazing and you just wonder how they manage to create all that."
And despite tight restrictions on who could gain access onto the 'City of Ember' set, Myles' mum Eimear and Rachel's mum Kate, both managed to watch some scenes being filmed.
Rachel explained; "We were sitting on the set and Soairse, who acted in 'Atonement' with Keira Knightly, came over and she was doing a crossword puzzle but needed some help, and my mum loves doing crosswords so she ended up helping Soairse fill it in."
The trio, who all aspire to become full-time actors when they grow up, praised drama teacher Pamela for the help she has given them. "She's a real inspiration to us. Pamela loves acting and she's really happy and delighted for us," added Rachel.
Now the friends face the difficult task of deciding who gets to come with them to premiere as they were all allotted only four tickets each.
"There are more books in the 'City of Ember' series and it looks like the film will be a big success, so we're hoping that if they make the sequel, 'The People of Sparks' we might be called back to be in it," added Rachel.