Decades prior to the book's opening, a magical race known as the Seerkind combined all of their powers to create a secret world known as "the Fugue", a carpet into which they wove their most beloved locations, animals, possessions and themselves as a safe haven. Their aim was to avoid persecution by humans (who call them demons and fairies) and eradication by a destructive being known as the Scourge. This creature's nature is entirely unknown to the Seerkind, as no-one has survived to describe it. The Fugue, resembling an ordinary, albeit exquisitely woven, carpet is left in the care of a normal woman, Mimi Laschenski, who married one of the Seerkind and resides in Liverpool, England.
Mimi reaches old age and is hospitalised following a stroke. A young man named Calhoun Mooney, chasing an escaped homing pigeon, accidentally glimpses the Fugue hidden in the carpet, which profoundly affects him. Simultaneously, Mimi's granddaughter Suzanna Parrish arrives in the city at Mimi's behest. The mystery surrounding Mimi and the full potential of the carpet brings Cal and Suzanna together and quickly into confrontation with the primary antagonists: Immacolata, an exiled and extremely powerful Seerkind bent on revenge; Shadwell, a human salesman with limitless ambition; and Hobart, a conscientious policeman.
Cal and Suzanna acquire new allies and abilities in their goal of protecting the Fugue from destruction, venturing into it themselves twice. When Shadwell's actions result in the Fugue's seemingly total obliteration, the surviving Seerkind scatter. In a last desperate attempt to finish them, Shadwell locates and awakens the Scourge, which begins systematically destroying any and all traces of magic it can find.
Cal, Suzanna and their remaining allies make a final stand against Shadwell by using his own tactics against him and convince the Scourge to abandon its cause and leave the planet in peace. In the aftermath, a severely traumatised Cal is cared for by Suzanna whilst their friends adjust to permanent life amongst humanity. Eventually, Cal emerges from his withdrawal with the knowledge of how the Fugue is still alive and can be restored to its full glory.
