'Thisseriesisamust-readforanyonewholovesthesea, or islands, or joyous, intricate story-telling.' ANN CLEEVES   Days before the final Shetland fire festival, in broad daylight, a glamorous young singer tumbles down a flight of steps. Though it seems a tragic accident, sailing sleuth Cass Lynch, a witness at the scene, thought it looked like Chloe sleepwalked to her death.   But young women don't slumber while laughing and strolling with friends. Could it be that someone's cast a spell from the Book of the Black Arts, recently stolen from a Yell graveyard?   A web of tensions between the victim and those who knew her confirm that something more deadly than black magic is at work. But proving what, or who, could be lethal - and until the mystery is solved, innocent people will remain in terrible danger...