The much-anticipated release of the latest Harry Potter book naturally led to a busy spell of activity as its contents were rapidly reduced to a summary for the Wikipedia article.
Last Saturday, within minutes of the book's midnight release in the UK, Harry Potter and the Half-Blood Prince was already being synthesized into Wikipedia content and the information distributed to appropriate articles. Occasional vandalism also appeared, but progress was generally smooth and managed to proceed without even requiring much discussion (the book's talk page has yet to be archived; by comparison, the talk page for the 7 July 2005 London bombings had to be archived four times in barely more than a day). As Elian noted, using the current event tag for a book is quite a rarity when that template is usually reserved for topics like elections or catastrophes.
The busiest location was of course the article dedicated to the book itself, which saw well over 1,000 edits within the first 24 hours. As a first step, the list of chapter titles was added, after which brief summaries of each chapter began to appear. The editors had only managed to get as far as Chapter 4 when somebody, apparently having skipped ahead rather than reading all the way through, revealed the ending and unveiled the answer to the book's mystery. Ultimately, the synopsis of all 30 chapters became too large for the main article and on Sunday it was split off into a separate article for the plot summary.
Meanwhile, all of the pre-publication rumours about the book's contents, which had been painstakingly chronicled in anticipation of the event, were relocated shortly before the magical hour to Harry Potter and the Half-Blood Prince (Crystal Ball). Later the page was nominated for deletion as "speculation and original research", but most people seemed to favor keeping it for historical reasons or simply merging useful material back into the main article.