When the matriarch of a British-Iranian family goes missing in London, her loved ones find themselves on an offbeat spiritual journey to track her down, setting their old world traditions on a collision course with their new world surroundings.

Inspired by her own Iranian roots, “Mercy” is the feature debut of British-Iranian director Mandi Riggi. Andrew Eaton (“The Crown”) will executive produce, with a cast that includes F. Murray Abraham, Hiam Abbass, Emun Elliott, Sarah Snook and Yasmin Paige. The film was selected for MIA’s co-production market and pitching forum.

“Mercy” draws on Riggi’s upbringing in the U.K., where she lived until the age of 14, after her parents left Iran in the wake of the 1979 revolution. Though they arrived “with hope in their eyes” and plans for a better life, the director said the bittersweet decision weighed on them long afterward.

“These are immigrants who can never go back to their own country,” Riggi said. “So I grew up with the kind of parents who are always looking back. There was a lot of nostalgia for a life that they could never have.”

Growing up, Riggi saw glimpses of Iranian life in the colorful diaspora community around her. As she later matured into an accomplished scripter and playwright, though, she avoided writing about her family life, and her relationship to her roots. “I never wanted to be typecast as that Iranian person who writes about Iranian things,” she said.

It wasn’t until her father became terminally ill that she decided to write a “love letter to my parents, and to their country of origin.” It was a difficult task. “I wrote it as a way to deal with the grief in advance,” she said. “It was like a cleansing to me.”

Riggi and producer Kevin Comer, of Psychonaut Films, have been in Rome looking to close more financing and meet with distributors.

Talks with a potential DoP are underway. Riggi said “Mercy” will be shot in the energetic vein of Pedro Almodovar, who the director said “does a lovely job combining comedy and tragedy.” She added that it would be a natural fit for her movie.

“Persian people…are larger than life characters,” she said. “They’re very boisterous. They wear their hearts on their sleeves.”