There are similarities to be found in the two plays by Nicola McCartney about to open in major theatres across the country over the next few weeks. In Heritage, the Belfast-born writer decamps emigres from Ulster to Canada in 1914. Here, a young woman called Sarah attempts to build a new life, but love across the barricades is blighted by hand-me-down myths about an Ireland that never really existed, with barely understood age-old battles fought on foreign soil.

How Not to Drown, meanwhile, tells the real life story of Kosovan refugee Dritan Kastrati, who co-writes and plays himself to tell the story of how, in the aftermath of the Kosovan War, he survived a perilous voyage across the Adriatic for a new life in Western Europe. Once in the UK, he is put through further turmoil in the British care system, surviving it to become the now twenty-something bundle of charisma he is today.

How Not to Drown is a brand new piece that forms one of the flagships of the Traverse Theatre’s Edinburgh Festival Fringe season. Heritage, which opens at Pitlochry Festival Theatre later this month, is a revival of a play first seen at the Traverse in 1998. As subjects and themes collide across the centuries, both plays seem totally of the moment.

“There are links,” says McCartney, who has lived in Glasgow since the 1990s. “Those links are about language and culture, but I think the real link is identity. That was one of the reasons for writing Heritage in the first place, and that definitely connects with How Not to Drown, because Dritan talks a lot about identity. You go somewhere and you’re considered an immigrant in the host country you move to, but then when you go back to the country you came from, you’re considered an immigrant there, because you don’t fit there either."

How Not to Drown is a co-production between the physical-based ThickSkin company, who first commissioned the play with the Lawrence Batley Theatre prior to the Traverse and the Tron Theatre, Glasgow coming on board. This was after McCartney had a conversation with Scott Graham from Frantic Assembly, who she had worked with in the 1990s, and who had worked with Kastrati as an actor. McCartney had recently returned from the United States, where she developed her play, Rachel’s House, with women who had come through the criminal justice system, and who now lived in a community recovery home in Ohio.

“Scott started telling me about Dritan,” says McCartney, “and how he’d come to Frantic Assembly through their young men’s project, Ignition. He’d been given a small bursary by the BBC to make his story into a piece of physical theatre, but he was finding it really hard to talk about it. He could only tell the funny bits, and wasn’t able to articulate what had happened to him, then Scott stopped and said, but you could make him talk.”

McCartney led a workshop with Kastrati and other young men, which led to one-to-one work, and “Within about an hour and a half he had said things he’d never said before. The first story he told me is the first scene in the play, which is based on a tradition of Albanian culture where you get thrown into the river by the bigger boys. That happened when he was six and he almost drowned, but he told it beautifully. He’s got a real poetic demotic.”

McCartney applied her own experience as a foster parent to Kastrati’s experience.

“I’m familiar with that system,” she says, “and am familiar with working with asylum seekers and refugees, who don’t have any control over their own narratives or stories, which are taken away from them. Dritan didn’t have a normal upbringing by any stretch of the imagination, and he saw a lot of horrific things. This was a boy who was taught to load an AK 47 with his feet when he was six years old during the Kosovan war in case his family were attacked but it’s a story of an ordinary kid getting thrown into an extraordinary situation, and it’s a quite humanising story about young unaccompanied asylum seekers.”

Other experiences have also fed into McCartney’s collaboration with Kastrati.

“It’s weird this is using so many different bits of me,” she says. “There’s the playwright bit, the applied theatre bit, and all that training with foster care working with people who are damaged or traumatised in some way. I think it was the fostering that re-engaged me with why I was making theatre in the first place, and why I wanted to write plays. I think I got my anger back. I rediscovered my rage. I’d always written plays about social justice, and I’d forgotten that was why I’d started.”

As McCartney stresses with a passion, however, How Not to Drown is as much Kastrati’s play as her own.

“What’s been really important from the beginning is that Dritan has a co-writing credit,” she says, “because it’s his story. I feel very scared of appropriating anyone’s voice, and having just my name on it would completely go against what it is I’m trying to do with the type of work I do, which is give people back control over their own story. That’s why I do this stuff. Because of the kids I’ve seen and the prisons I’ve worked in, so many people have such a fractured sense of themselves. The story we tell to ourselves about ourselves is really important, for mental health, but also politically in that that these stories are told by the people who own them.

“How Not to Drown has been a labour of love. There’s been a lot of belief in the why of this play, and the fact that it’s is dealing with so many things that are pertinent right now in our society. It’s the same with Heritage. It’s twenty-one years old, but it looks at a situation that could very easily be resurrected by the psychodrama we’re currently living through as a set of nations. But theatre is a massive empathy machine, and if it does anything, it gets people talking about things that are happening in the culture we’re living through now, both here and internationally.”

Heritage, Pitlochry Festival Theatre, in rep July 25-September 26; How Not to Drown, Traverse Theatre, Edinburgh, July 30-August 25.