"His Majesty's Dragon" by Naomi Novik is a 384-page mass-market paperback published in 2006 by Del Rey Books. The book is written in English and follows the story of a young mathematician named Lev Grossman who is recruited by the government to solve a mysterious explosion in Washington, D.C. The novel is the first book in the fantasy series "The Magicians" and is highly praised for its engaging storyline and well-developed characters. With its captivating narrative and intricate world-building, "His Majesty's Dragon" is sure to appeal to fans of the fantasy genre.