Circle of Magic: #4 Healing in the Vine

Plague has struck Summersea - a deadly blue pox like nothing the healers have ever seen, and that spreads wildly. Forced into quarantine by exposure to the outbreak, Briar and his teacher fight to keep the victims alive. The Winding Circle mages must find the key to countering the disease, and fast, or Summersea will become a city of the dead.