Later in the novel, Boa searches for Christopher Carrion on Gorgossium and (failing to find him) captures Finnegan Hob, her former fiancé.

Pursued by Mater Motley's subordinates, Candy falls in love with a boy named Gazza, who immediately requites the affection.

At the climax of this installment, Mater Motley releases the arthropod 'Sacbrood', who in turn cover the sky and give the book its name, and collaborates with the extraterrestrial Nephauree, who seek to dominate the Abarat.

Having fallen from the Abarat into the 'Void' beyond, Candy, Malingo, and Gazza enter another, unidentified parallel universe, concluding the book.

Barker acknowledges his heroine's literary lineage, but he also crafts a wonderfully contemporary girl who is brave, resourceful, loyal and willing to sacrifice herself for the betterment of the world".