The Shadow Song

The final book of the Cursed Melodies trilogy follows Gwen and Jonas who, after escaping the Shadow Library, must reach out to unlikely allies to help them find some way to defeat the Shadowling and save Astrid. The solution, they are told, lies in what really happened between the Shadowing and King Arthur all those years ago. Their quest will take them far south to the Moroccan desert and its secret forests.
But all is not as it seems: the story of the Shadowling is shrouded in mystery, and at the heart of it all lies Arthur's sword, a weapon forged of the most powerful magic of all, a power that could save or end them all. Meanwhile, Astrid has been unleashing chaos around the world at the Shadowling's command, pushing the Order to its limits. But even cursed, Astrid's curiosity remains. She has become the Shadowling's favourite, and with each order she finds herself dwelling on the parts of history her new master still keeps hidden from her.
And that is not all: she is keeping secrets of her own. Memories she would rather destroy keep rising to the surface, and she cannot quell her obsession with Gwen. Ultimately, Gwen must make a shocking decision in the hopes of saving Astrid and the world. The fate of all lies in their hearts.