“There’s more at stake here than Dan Brown’s royalties. If the judge in London rules that the set of ideas Leigh and Baigent espoused can be copyrighted, it would set a troubling precedent that could trip up authors and filmmakers who craft works around any new historic or scientific research. It’s worth noting that a federal judge in New York rejected a lawsuit against Brown last year by novelist Lewis Perdue, saying any similarity between their books was in ideas that could not be copyrighted.”