In her first adventure, Ista Flit and her friends saved the town of Shelwich from a monstrous foe--but her father is still missing.

She has a new clue though: a key, engraved with mysterious symbols, and a note saying "any door with a keyhole will do."

This key transports Ista, Nat, and Ruby to Glass Island--where creatures Ista thought were mythical turn out to be very, very real. A sinister wraith haunts the reed-beds, and deviously seductive, fairy-like marsh spinners lure people in to dance at their revels--and never let them go.

Ista is sure her father must be trapped in the marsh spinner's lair. She's determined to devise a plan cunning enough to infiltrate the revels and rescue Pa.

When the tide is high and magic is at its peak, Ista and her friends will face off with the trickiest creatures imaginable. Can they win Ista's father's freedom? Or will the revels claim three new dancers forever...?