Stewart's deep ties to French cinema are well-documented; she remains the only American actress to have won a César Award, receiving the Best Supporting Actress honor in 2015 for her role in Assayas' Sils Maria. This pivotal win cemented a significant artistic partnership that continued with the critically lauded Personal Shopper in 2016, which earned Assayas the Best Director prize at Cannes, and the 2022 HBO series Irma Vep. Her ongoing engagement with French projects also includes an upcoming role in Quentin Dupieux's Full Phil.

Spiritual World, first reported by Ioncinema, will see Stewart portray Ada, a young woman grappling with clairvoyant abilities and unsettling premonitions. This premise immediately evokes comparisons to her character in Personal Shopper, where she played a medium attempting to communicate with her deceased twin brother. Assayas appears keen to revisit and expand upon these spectral themes with Stewart at the helm once more.

The film is drawing considerable attention not just for its lead but also for its star-studded supporting cast. Joining Stewart are Vicky Krieps, celebrated for her roles in Phantom Thread and Bergman Island; Niels Schneider, known for The Unknown Girl; Wagner Moura, an Oscar nominee for Narcos and Secret Agent; Riley Keough, who has garnered acclaim for The House That Jack Built and Under the Silver Lake; and the legendary Barbara Sukowa, a frequent collaborator with German New Wave directors Rainer Werner Fassbinder and Margarethe von Trotta. Notably, Stewart and Moura are also set to appear together in Panos Cosmatos' vampire film Flesh of the Gods.

Stewart's career continues to evolve with a diverse and compelling filmography. Following her Oscar nomination for Spencer, she has delivered memorable performances in films such as Kelly Reichardt's Certain Women, David Cronenberg's Crimes of the Future, and Rose Glass' Love Lies Bleeding. She also recently made her feature directorial debut with the acclaimed The Chronology of Water. This new venture with Assayas further solidifies her reputation as an actress drawn to challenging, distinctive roles.

Production for Spiritual World is slated to begin in early 2027, promising another intriguing entry in the collaborative history of Stewart and Assayas.