Tales of Jesus and Mary Magdalene returned to a London court Tuesday, as two authors appealed a ruling that Dan Brown did not infringe their copyright with his best-selling thriller “The Da Vinci Code.”

Lawyers for Michael Baigent and Richard Leigh — who face a bill for more than 1 million pounds ($2 million) if the original verdict stands — claim that Brown stole significant parts of his novel from their nonfiction work “The Holy Blood and the Holy Grail,” first published in 1982.