The Healing of the Vine (Circle of Magic)

Summersea faces terrible danger...
Plague has struck the city. A blue pox - like nothing the healers have ever seen. It spreads rapidly and its touch is deadly.\nTime is running out...
Forced into quarantine by exposure to the outbreak, Briar and his teacher, Dedicate Rosethorn, fight to keep the victims alive. But their magic has limits - it offers comfort, but no cure. The Winding Circle mages must find the key to countering the disease, and fast, or Summersea will become a city of the dead.