Across the wall.Garth Nix. 2005.

Nicholas Sayre will do anything to get across the wall, back to the Old Kingdom. Thoughts of Lirael and Sam haunt his dreams. But here in Ancelstierre the Charter is dormant, and before Nick can re-join his friends he must face one of the rarest and most dangerous of the Free Magic creatures: a creature that seems to draw power from Nicholas himself.

’Nicholas Sayre and the Creature in the Case’ opens this superb collection of short stories that range from classic fantasy to a gritty urban version of Hansel and Gretel, and an unusual take on nature in matters of the heart.