“Two authors who failed to convince Britain’s High Court that New Hampshire’s Dan Brown stole their ideas for his blockbuster novel ‘The Da Vinci Code’ took their case to the Court of Appeal on Tuesday. Lawyers for Michael Baigent and Richard Leigh, who face a bill of more than $2 million if the earlier verdict stands, said the lower court ruling ‘was based on a misunderstanding of the law and of the claim.’ “