"The Princess in Black and the Perfect Princess Party" is a children's book written by Shannon Hale and Dean Hale. It features the character Princess Magnolia, who is also the superhero known as the Princess in Black. In this story, she faces the challenge of balancing her royal duties with her secret life as a crime-fighter. As the princess prepares for a grand party, she must deal with unexpected interruptions from monsters. The narrative highlights themes of friendship, bravery, and the importance of being true to oneself. The book is part of a popular series that combines adventure with humor, appealing to young readers.