James McAvoy delivers an entirely improvised performance in first trailer for thriller My Son

Get ready for a performance like no other. James McAvoy stars in thriller My Son, but there’s a catch: the X-Men: First Class actor wasn’t given a script.

That’s not a mistake on the studio’s part. In what’s described as a "groundbreaking filmmaking experience," his entire performance is improvised from start to finish. We can even catch a glimpse of what that looks like – the trailer for My Son has just been released.

McAvoy plays Edmond, the father of a seven-year-old boy who has gone missing. He reconnects with his ex-wife (played by Claire Foy) in search of answers, though his mysterious past looks set to catch up to him.

So far, so ordinary – but it’s McAvoy’s reactions dotted throughout the trailer that will have you intrigued.

According to The Hollywood Reporter, McAvoy is aware of the "basic aspects" of the story, and must drag Edmond from A to B. Is he hiding something? Will he uncover the truth? As the conspiracy grows, it all adds up to a tantalizing prospect for both actor and audience member. It can’t hurt that, especially given those gorgeous coastline shots, we’re getting some serious Broadchurch vibes from My Son too.

"I’ve managed to have an experience that no actor gets to have," McAvoy said. "I hope we’ll give the audience something really tangible that they can hang on as this thriller rattles along."

No word yet on a UK release, but it’s out Stateside on streaming service Peacock from September 15. For more from cinemas and streaming, here’s our guide to movie release dates.

Bradley Russell

I'm the Senior Entertainment Writer here at GamesRadar+, focusing on news, features, and interviews with some of the biggest names in film and TV. On-site, you'll find me marveling at Marvel and providing analysis and room temperature takes on the newest films, Star Wars and, of course, anime. Outside of GR, I love getting lost in a good 100-hour JRPG, Warzone, and kicking back on the (virtual) field with Football Manager. My work has also been featured in OPM, FourFourTwo, and Game Revolution.