Charlie Bone and the invisible boy
(Book)

Charlie and his friends unite to rescue Ollie, a boy who was turned invisible and made to live in the attics at Bloor's Academy more than a year ago, but they are hindered by a mysterious new student who lives with Charlie's aunts. In the ruins of the castle of the Red King, Charlie and tancred discover a tree-girl that whispers secrets to them and asks for their help in restoring her to a real girl. When Charlie returns to help her, he finds that the tree has been destroyed. Meanwhile, the yewbeam sisters are trying to marry Amy Bone, Charlie begins to hear portraits speaking, and a new music teacher has arrived at bloor's academy. Soon Emma discovers that the invisible boy living upstairs in the attic is her older brother, and when Manfred finds out their plans, he threatens to lock up Emma.