Castle is the second book in Garth Nix's The Seventh Tower series, published on 1 November 2000 by Scholastic.

[1] The cover design and art are by Madalina Stefan and Steve Rawlings respectively.

Tal and Milla make it from the shadowy 'Dark World' to the titular castle, a seeming place of peace.

The two must avoid conspiracies and other dangers inside the castle, just to survive.

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