Bloomsbury 21 is a series of 21 books published in 2007 by Bloomsbury to celebrate their 21st anniversary.
 The books are limited editions of 21 of Bloomsbury's most famous published works.
 The books have covers featuring a white background with a picture of the original cover of the particular book, tilted in such a way that part of the picture is cut off and appears on the next book in the series.
 When the books are placed side by side in numerical order, their covers form a panorama of the 21 original book covers.
 Each book features an introduction by a fellow author and reading group guides.
 On the spine of each book is its number in the series above the number 21 to indicate the book's place within the series.
 Authors whose works have been included in the series include Margaret Atwood and J.K. Rowling.
The "Harry Potter" series of fantasy novels by J. K. Rowling have become some of the most widely read works of children's literature in history, with readers of all ages and in many countries.
 In April 2011 worldwide sales of Harry Potter books were estimated to be about 450 million copies.
 Oddly enough, it has been difficult to accurately determine with any degree of certainty exactly how many languages Harry Potter has been translated into.
 As best as can be determined (as of 2017), The Philosopher's Stone has been officially translated from the original English into 73 other languages.
 A 74th language, Scots, was announced on 2017-06-28 and it is expected to be available in October, 2017.
 Both Bloomsbury's and J.K. Rowling's sites have recently stated that the books have been translated into 79 languages (80 with the 2017-06-28 announcement of Scots); however, it has been argued that number actually represents the number of authorized translations (of The Philosopher's Stone) plus the original English.
 The number of authorized translations is not equal to the number of languages because there have been multiple authorized translations into the same language.
 Specifically, there have been two separate translations into each of: Mandarin Chinese, Portuguese, Romanian, Russian and Turkish (5 languages).
 English is often included in the list of translations even though technically it should not be (indeed, it is why our list here counts up to 74).
 Thus: 79 − English − 5 double-translations = 73.
 It is also worthwhile to emphasize that not all seven books are have been translated into these 73 languages.
Harry, A History: The True Story of a Boy Wizard, His Fans, and Life Inside the Harry Potter Phenomenon is a 2008 book by writer and webmistress of The Leaky Cauldron, Melissa Anelli.
 The book describes the "Harry Potter" phenomenon in detail.
 The book was published on November 4, 2008, by Pocket Books, and debuted at #18 on "The New York Times" paperback bestseller list.
 Notably, the book features exclusive interview material and insights from Harry Potter author J.K. Rowling who also wrote the foreword.
Several actors of the United Kingdom and Ireland have voiced or portrayed characters appearing in the "Harry Potter" film series based on the book series by J. K. Rowling.
 Daniel Radcliffe, Rupert Grint and Emma Watson have played Harry Potter, Ron Weasley and Hermione Granger in all the films.
 When they were cast only Radcliffe had previously acted in a film.
 Complementing them on screen are such actors as Helena Bonham Carter, Jim Broadbent, John Cleese, Robbie Coltrane, Warwick Davis, Ralph Fiennes, Michael Gambon, Brendan Gleeson, Richard Griffiths, Richard Harris, John Hurt, Jason Isaacs, Miriam Margolyes, Helen McCrory, Gary Oldman, Alan Rickman, Fiona Shaw, Maggie Smith, Timothy Spall, Imelda Staunton, David Thewlis, Emma Thompson, and Julie Walters, among others.
 Thirteen actors have appeared as the same character in all eight films of the series.
Harry Potter and the Chamber of Secrets is a 2002 British-American fantasy film directed by Chris Columbus and distributed by Warner Bros.
 Pictures.
 It is based on the novel of the same name by J. K. Rowling.
 The film is the second instalment in the long-running "Harry Potter" film series.
 It was written by Steve Kloves and produced by David Heyman.
 Its story follows Harry Potter's second year at Hogwarts School of Witchcraft and Wizardry as the Heir of Salazar Slytherin opens the Chamber of Secrets, unleashing a monster that petrifies the school's denizens.
 The film stars Daniel Radcliffe as Harry Potter, with Rupert Grint as Ron Weasley, and Emma Watson as Hermione Granger.
 The film is also the last film to feature Richard Harris as Professor Albus Dumbledore, due to his death that same year.
Pottermore is the digital publishing, e-commerce, entertainment and news company from J.K. Rowling and is a global digital publisher of Harry Potter and J. K. Rowling's Wizarding World.
 It offers news, features, and articles as well as new and previously unreleased writing by J.K. Rowling.
 The site features Rowling's thoughts, several pages of unpublished text, and a sales resource for e-book and audiobook versions of the seven "Harry Potter" novels.
Magic Beyond Words: The J.K. Rowling Story is a made-for-TV film starring actress Poppy Montgomery.
 It is based on the book "J.K. Rowling A Biography", by Sean Smith, detailing the journey of struggling single mother J. K. Rowling, her bid to become a published author, and her rise to fame that followed the publication of "Harry Potter and the Philosopher's Stone".
Sam Clemmett is a British actor.
 Born in Brundall, Norfolk, Clemmett began his acting career in 2013.
 He is known for being cast as Albus Potter in 2015 for the British play Harry Potter and the Cursed Child.
 His performance in the play has made him popular with Harry Potter fans, as well as the creator of Harry Potter, J.K. Rowling.
 Rowling stated that, "There's much I could say about Sam-as-Albus, but we'd be into spoiler territory so quickly I'll just say we couldn't have cast better."
 He played the role in the West End, until late-Spring 2017.
The Magical Worlds of Harry Potter: A Treasury of Myths, Legends, and Fascinating Facts is a guide to the fictional "Harry Potter" universe, written by David Colbert.
 It explores the references to history, legends, and literature in J.K. Rowling's "Harry Potter" novels.
 Colbert conceived the idea for "The Magical Worlds of Harry Potter" while quizzing his nephew and nieces about the mythological references in the novels.
 He later wrote the book while teaching a seminar on self-publishing to graduate students at the University of North Carolina.
 The book was published in March 2001, without approval from Rowling, and has since received positive reviews from critics.
 An updated version of "The Magical Worlds of Harry Potter" was published in 2004 by Berkley Books.
Hermione Jean Granger ( ) is a fictional character in J. K. Rowling's "Harry Potter" series.
 She first appears in "Harry Potter and the Philosopher's Stone", as a new student on her way to Hogwarts.
 After Harry and Ron save her from a mountain troll in the girls' toilets, she becomes best friends with them and often uses her quick wit, deft recall, and encyclopaedic knowledge to help them.
 Rowling has stated that Hermione resembles herself at a younger age, with her insecurity and fear of failure.

Question: Which J.K. Rowling book does Emma Watson's character first appear in?
Answer: "Harry Potter and the Philosopher's Stone"