MULL is the place to find the white-tailed eagle, the pink-footed goose, whales, dolphins and otters.

It doesn’t do too badly for greater-crested filmmakers either. To a list of credits that includes Powell and Pressburger’s I Know Where I’m Going!, Sean Connery’s Entrapment and Michael Caine’s Kidnapped, Mull can now add a starring role in a new drama, Island.

Adapted from the novel by Jane Rogers, Island stars Colin Morgan (of Merlin fame), and Natalie Press (My Summer of Love, Red Road) in the story of a troubled young woman confronting her past.

Shot on Mull, and in other parts of Argyll and Bute, Island could also serve as a lesson in what it takes to get an independent British film made, or a cautionary tale about the rigours of shooting in Scotland in winter.

Morgan, 25, reckons he wore at least eight layers of clothing, including three pairs of trousers, to combat the cold. “And then there was the day we had to run into the sea. This was all in December.”

Morgan plays Calum, who has lived on the island all his life and is obsessed with its past in the same way that Nikki (Press) is consumed by her own. “He’s obviously very different,” says Morgan of his character. “But I certainly didn’t want to play a syndrome or a condition. I created my own world to live in, which is what Calum did, filling my head with lots of traditional Scottish fairy tales and folklore, Norse mythology as well.”

During breaks in filming he also wandered the island. “Slightly method, but it was great to take yourself off on your own. I remember walking a whole day and the only thing I came across was a herd of stags that stopped, stared at me for ages, then took themselves off.”

All a touch more scenic than Merlin, which Morgan describes as being filmed “in a tin shack in Cardiff”. Shooting has begun on the fourth series, which will air this autumn. An origins story about the boy wizard (not that one) and Arthur, Merlin has been a sleeper hit for the BBC, despite being received like a cup of cold gruel by some critics when it first aired three years ago. It has built up a loyal fan base here, with sales in America, Japan, France, Greece and other countries following.

“As it has gone on it has grown,” says Morgan. “When we started out it was very much a young, family drama. It’s found other tones, ways to touch other generations, so now the whole family can sit down to it, youngsters, teenagers, adults, grandparents, and get something different from it.”

Morgan and his co-star Bradley James, who plays Arthur, became so fascinated by Arthurian legend they took a road trip around Wales to learn more. The TV series, he says, is just the latest retelling of a story that has, like Merlin’s spells, been spun and spun again. Fans of the series who go to see Island will find Morgan using a very different, lower-key acting style. With Merlin, he says, everything is heightened and out in the open.

“Because it’s being told through my eyes, I have to make it clear what I’m thinking all the time, so kids watching can know Merlin’s worried, Merlin’s unhappy.” In Island, he says, it’s about what you don’t say. “You’ve got the back story and it’s all in your head, it’s there. When it’s shown on the big screen it’s big enough to be seen, hopefully.”

Island had its world premiere at the Glasgow Film Festival in February. The setting, in the Cineworld cinema on Renfrew Street, was a familiar one for Morgan. While a student at the RSAMD down the road, he worked in the cinema’s cafe-bar. “I was coming up the escalators having flashbacks of carrying rubbish down,” he told the Q&A audience. Going back there for the premiere was “a surreal experience”, he laughs.

Morgan, born in Armagh, had originally planned to travel for a year after leaving the Belfast Institute of Further and Higher Education. But a friend had an audition for the RSAMD so Morgan applied as well, not expecting to get in but doing it for the experience. After a phone call the next day offering him a place he moved to Glasgow for three years. “Brilliant times,” he says. “I loved every second.”

The RSAMD years paid off, with Morgan going from graduation to a part in a production of Vernon God Little at the Young Vic. Other theatre roles followed, but it was Merlin that won him a Variety Club award for outstanding newcomer, and brought him fan attention or, as he calls it, “fan support”.

He gets a lot of letters. Well brought-up lad that he is, Morgan responds in person. “I try my best to get through them all personally. If someone has taken the time to send me a letter I’ll take the time to send one back.”

Besides being a homecoming of sorts for Morgan, the Glasgow premiere was a “terrifying and brilliant” experience for directors Elizabeth Mitchell and Brek Taylor. After a long time sharing the film with no-one but a sound editor, this was big-screen, big-crowd time for the pair.

“It made it all worthwhile,” says Taylor. It took five years from first reading Rogers’ book to getting the film on screen. Raising the money was the usual slog, and finding the right location was crucial. After six months looking around the islands, they found their idea of filmmaking heaven on Mull.

Then came the practicalities, such as not being able to get a signal for mobile phones or walkie talkies. At one point the crew had to be positioned in a chain along the road to shout instructions down the line. “It felt like we were shooting back in the old days of I Know Where I’m Going,” says Mitchell of Powell and Pressburger’s 1945 classic.

As for directing their first film together, both Taylor and Mitchell, who had to take on other jobs while keeping the picture going, say they wouldn’t have had it any other way. “It was difficult at times, certainly our relationships with friends and family were under strain because we never really saw them, we were under huge financial strain, all these things, yet we were in it together,” says Mitchell. “When people say ‘how can you direct together’ I say ‘how can you not?’.”

They are hoping to take the film back to Mull. It will be a chance for islanders to see how the place has changed since those Powell and Pressburger days. Mull, once again, is ready for its close up.

Island is showing at the Filmhouse, Edinburgh, on May 10, and Glasgow Film Theatre, May 11 (Q&A with Elizabeth Mitchell on both dates), then at Eden Court, Inverness, June 16-21.