Netflix has added four more actors to the cast of its television adaptation of Dan Brown's novel The Secret of Secrets, joining previously announced leads Morgan Spector and Rebecca Hall. Cherry Jones, Corey Stoll, Rob Delaney and Abbey Lee will take on supporting roles in the as-yet untitled series, which is being developed by Brown alongside Lost showrunner Carlton Cuse. The project matters for Netflix as it builds out another instalment in the hugely popular Robert Langdon franchise, following films and series based on The Da Vinci Code and Angels & Demons.

Spector will play symbologist Robert Langdon and Hall his scientist girlfriend Katherine Solomon, while the new arrivals take on key supporting characters: Jones as US Ambassador Heide Nagel, Stoll as former CIA agent Everett Finch, Delaney as editor Jonas Faukman, and Lee as research assistant Sasha Vesna. The novel, published by Doubleday in September 2025, follows Langdon racing to save a missing scientist and a manuscript that could transform understanding of the human mind; Brown's books have sold more than 250 million copies in 56 languages. The series, which landed at Netflix in May 2025 with a straight-to-series order, is executive produced by Cuse, Brown, Emma Forman and Zoe Robyn.