Lady Friday tempts Arthur with an unexpected offer - but it is a cunning trap for the Rightful Heir to the Kingdom, or a chance he must seize before Superior Saturday or the Piper snatch it first? Who will win the race to discover the secret of the Middle House?

Arthur Penhaligon has wrested five of the Keys from their immortal guardians, the Trustees of the Will. But gaining the Sixth Key poses a greater challenge than any he has ever faced before. Superior Saturday is not just one of the Trustees, she is also the oldest Denizen and the most powerful and knowledgeable sorcerer within the House. She has tens of thousands of sorcerers at her command - and she has been preparing her forces all along.

Seven days. Seven keys. Seven virtues. Seven sins. One mysterious house is the doorway to a very mysterious world - where one boy is about to venture and unlock a number of fantastical secrets. As Arthur gets closer to the heart of his quest, the suspense and mystery grow more and more intense.

Arthur Penhaligan has wrestled five of the Keys from their immortal guardians, the Trustees of the Will. But gaining the Sixth Key poses a greater challenge than any he has faced before. Superior Saturday is not just one of the Trustees - she is also the oldest Denizen and the most powerful and knowledgeable sorcerer within the House.

Four of the seven Trustees have been defeated and their Keys taken, but for Arthur, the week is still getting worse. Suzy Blue and Fred Gold Numbers have been captured by the Piper, and his New Nithling army still controls most of the Great Maze. Superior Saturday is causing trouble wherever she can, including turning off all the elevators in the House and blocking the Front Door.

Lirael has never felt like a true daughter of the Clayr. Abandoned by her mother, ignorant of her father's identity, Lirael resembles no one else in her large extended family living in the Clayr's glacier. She doesn't even have the Sight, the ability to See into the present and possibly futures, that is the very birthright of the Clayr.

Before she went to join Sam and Mogget downstairs, Lirael paused for a moment to look at herself in the tall silver mirror that hung on the wall of her room. The image that faced her bore little resemblance to the Second Assistant Librarian of the Clayr. She saw a warlike and grim young woman, dark hair bound back with a silver cord rather than hanging free to disguise her face. She no longer wore her librarian's waistcoat, and she had a long Nehima at her side rather than a library-issue dagger.

On the fourth day there was war. Following their adventures in the Border Sea, Arthur and Leaf head for home. But only Leaf gets through the front door. Arthur is blocked because someone, or something, has assumed his identity and is taking over his life. Before Arthur can take action, he is drafted by Sir Thursday and forced to join the Glorious Army of the Architect.

Wednesday has rolled around, and Arthur Penhaligon has an invitation to return to the House that he can't refuse. Drowned Wednesday has sent a ship to pick him up from the hospital...even though his hometown is miles away from any ocean.

Arthur doesn't think he'll have to return to the strange house that nearly killed him on Monday, the house that contains an entire world. But Tuesday brings new challenges: the enemy Grim Tuesday, who threatens the well-being of both Arthur's family and his world. Arthur must retrieve the Second Key from Grim Tuesday in order to save everything; an adventure that will include stealing a Sunship, fighting the void-like Nithlings, and traveling in the scary Far Reaches for the ultimate showdown.