Prague is not pretending to be somewhere else

Production has officially begun in the Czech capital, where much of Brown's 2025 novel takes place. Netflix marked the September 4 announcement with its first behind-the-scenes image of Spector as Robert Langdon and Hall as Katherine Solomon.

Filming had already been visible around Old Town and Josefov, including locations near the Rudolfinum, Čechův Bridge and Prague's Municipal House.

For a Langdon story, that matters. Architecture, art and historical geography are usually part of the puzzle rather than decorative scenery.

This Robert Langdon is not being built around Tom Hanks

Spector inherits one of the most recognizable modern literary roles on screen. Tom Hanks played Langdon in Ron Howard's The Da Vinci Code, Angels & Demons and Inferno, while Ashley Zukerman later portrayed a younger version in Peacock's short-lived The Lost Symbol.

Showrunner Carlton Cuse has focused his description of Spector on intellect, curiosity and humanity. Those qualities offer a useful way to reset the character without treating the Netflix project as a fourth Tom Hanks movie stretched across television.

Spector's Langdon is still a Harvard professor and symbologist whose expertise in religion, art, history and symbols repeatedly puts him inside mysteries with consequences much larger than academia.

Katherine Solomon changes the emotional shape of the series

Rebecca Hall plays Katherine Solomon, the scientist Langdon is trying to rescue after she disappears with a groundbreaking manuscript at the center of the story.

Cuse has described Katherine as Langdon's first serious love interest. That relationship is one of the aspects he believes can move the character somewhere new on screen.

Hall and Spector are married off screen, an unusual piece of casting trivia that becomes more interesting because the adaptation is deliberately placing their characters' relationship closer to the center of the story.

Netflix added another five recurring players as filming began

Mamoudou Athie will play Michael Harris, Ben Levi Ross is Alex Conan, Anamaria Marinca is Dr. Gessner, Richard Sammel plays Karl Muller, and Elena Saurel has been cast as Susan Housemore.

They join Cherry Jones as Heide Nagel, Corey Stoll as Everett Finch, Rob Delaney as Jonas Faukman and Abbey Lee as Sasha Vesna.

Dan Brown and Cuse co-created the adaptation. Cuse is showrunner, writer and executive producer, with Brown, Emma Forman and Zoe Robyn also executive producing.

The television format is part of the pitch

Cuse has been unusually explicit about why Langdon is returning as a series. Brown's novels combine chase mechanics with history, science, theology and large philosophical detours, and a feature film has to discard a great deal of that material simply to keep moving.

Cuse has described the new adaptation as an eight-hour opportunity to explore that breadth. The Secret of Secrets gives him particularly strange material to work with, combining futuristic science and mystical lore around discoveries that could alter humanity's understanding of consciousness.

The story still has a missing scientist and a ticking clock. It just has more room between them.

One mystery is extremely mundane: the show still needs a title

Netflix continues to call the project an untitled series set in the world of The Secret of Secrets. The book title has become a convenient shorthand in coverage, but it has not been announced as the final television title.

There is no premiere date either.

What Netflix can confirm now is simpler: Morgan Spector is Robert Langdon, Rebecca Hall is Katherine Solomon, and production is underway in Prague.