Rebecca Hall has been confirmed as Katherine Solomon in Netflix’s forthcoming series based on Dan Brown’s 2025 novel *The Secret of Secrets*. She will appear opposite her husband, Morgan Spector, as recurring protagonist Robert Langdon, marking a significant casting step for Netflix’s new adaptation of Brown’s internationally successful Langdon stories.

The story follows Langdon as he tries to rescue a missing scientist and her potentially transformative manuscript while confronting ancient forces. Katherine is both a scientist and Langdon’s girlfriend; the series, co-created by Brown and showrunner Carlton Cuse, received a straight-to-series Netflix order in May 2025. Previous Langdon film adaptations starring Tom Hanks grossed about $2.24 billion worldwide by 2025.