Briar's Book by Tamora Pierce, is a fantasy novel set in the fictional duchy of Emelan. It is the fourth and final book in the Circle of Magic quartet, starring the four young mages Sandry, Tris, Daja and Briar as they learn to handle powerful magic, form intense bonds of friendship and stand up against destructive forces of nature. Plot introduction The main protagonist of the book is Briar Moss, a young ex-thief and "green" or plant mage, having ambient magic with all forms of plant life. Through his eyes the book explores themes of poverty and social injustice, as a deadly plague named the Blue Pox strikes The Mire, the poorest quarter of Emelan's capital city, Summersea. Plot summary To Briar, the Mire is familiar territory, having been first a street-rat and then a thief in Deadman's District, the poorest quarter of his native Hajra, before his magic was discovered by the great mage Niklaren Goldeye and he was taken to Winding Circle, a temple school for ambient mages. One day while out running errands with his teacher, Rosethorn, Briar is summoned to the Mire to examine Flick, a poor friend affected by a strange illness. Puzzled by what he has encountered, Briar enlists Rosethorn's help. The two bring the feverish girl to Urda's House, (a small charity hospital), where they learn that Flick is by far not the only one affected; many other people from the poorest parts of Summersea are ill as well. They also learn, to Briar's dismay, that the hospital has been put under quarantine to help stop the "blue pox"—so named for the bluish sores that mark the skin—from spreading even further. Trapped in Urda's House due to the quarantine, Rosethorn and Briar are kept busy with caring for the patients. Together with the healers, they come to the conclusion that it isn't the blue spots that are necessarily dangerous, but the fever. Even more troubling is the fever's apparent resistance to willowbark tea, a usually successful remedy. These revelations don't make the task of caring for patients any easier, however, and over the next few days many of them—including Flick—pass away. Eventually it's realized that the quarantine on Urda's House is useless; the plague has already spread to the whole of Summersea. Briar and Rosethorn are given leave, and travel back to Winding Circle, where Sandry, Tris and Daja spend the night with