Dan Brown, the world’s most famous author of thrillers and the man behind the global phenomenon of The Da Vinci Code, has recently announced the sixth installment in the Robert Langdon series. Titled The Secret of Secrets, the book will be out in dozens of languages—including English, of course—on September 9, 2025.
According to the synopsis of the book, which has been uploaded to Dan Brown’s official website, the book will see Robert Langdon, an esteemed professor of symbology at Harvard University, travel to Prague to attend a groundbreaking lecture by Katherine Solomon, a prominent noetic scientist.
Yes, as often happens when Langdon is around, a brutal murder catapults the trip into chaos, and Katherine suddenly disappears along with her manuscript, which is believed to hold explosive discoveries about the nature of human consciousness and which threatens to disrupt centuries of established belief.
“Langdon then finds himself targeted by a powerful organisation and is hunted by a chilling assailant sprung from Prague’s most ancient mythology. As the plot expands into London and New York, Langdon desperately searches for Katherine . . . and for answers,” the synopsis reads.
The Secret of Secrets is the sixth installment in the series, with the other titles including Angels & Demons (2000), The Da Vinci Code (2003), The Lost Symbol (2009), Inferno (2013), and Origin (2017). The first two, as well as Inferno, were turned into Hollywood movies, famously starring Tom Hanks and Professor Langdon.