In the ruins of the castle of the Red King, Charlie and Tancred discover a tree-girl who 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. 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.