The Swedish actor is playing a bamboozled police officer in What Remains, a film written by his wife and starring one of his sons. He looks back on mixing Marvel with arthouse, taking risks with Lars von Trier and Sweden joining Nato

Stellan Skarsgård is speaking to me from his cabin, outside Stockholm, and why shouldn’t he look relaxed and happy, in those clement, sun-dappled surrounds? But it is so disconcerting. His performance in What Remains, as a battle-scarred police officer, trying to keep hold of his family, his bearings and his scepticism in the face of a criminological modernity that puzzles him, joins a body of knotty work that UK audiences would probably date back to Breaking the Waves, Lars von Trier’s 1996 classic. His smallest facial gesture speaks fathomless emotion. I am a huge Mamma Mia! fan – in which he plays Bill Anderson – so I have seen Skarsgård smile, but even then, not all the time.

What Remains is based, loosely, on a famous case in Sweden: it was the 90s, and the so-called “retrieved memory” technique was huge, even though in the US, where it was developed, it had already been disallowed as reliable evidence. “All psychologists in Sweden were using retrieved memory at the same time, a lot of men were put in jail for violating their children,” Skarsgård says. “It’s really the fabrication of memory. It was very optimistic, to think you can just open up the memory and look at it. Every divorce you’ve been through, you’ll know, the truth isn’t exactly as everybody says.”