The fantastic conclusion to Garth Nix's New York Times bestselling series. On the seventh day, there was a choice. The House is falling apart, and when it is destroyed, all existence will be destroyed with it. Arthur Penhaligon and his friends Leaf and Suzy are caught in the chaos, separated by events but drawn together in their fight to survive. They must use every power at their disposal-magical or practical-to defeat the enemies attackingthem from all sides. For Arthur, the most formidable challenge comes from Lord Sunday, the most elusive of the Trustees of the Will. Lord Sunday's magic is unlike anything Arthur has encountered before-and his secrets have the potential to destroy not only Arthur, but also all the people he holds dear. On Monday, Arthur Penhaligon was just an ordinary boy thrust into an extraordinary situation. From Tuesday to Saturday, he emerged as the Rightful Heir to the Architect who created everything within the House. Now, on Sunday, he will face a choice of astonishing proportions-and a remarkable conclusion to a completely unforeseen adventure.