From Lost Fables Wiki
Extremely infectious. Almost any known vector can spread the plague, though thankfully it does not survive long outside of a host, nor does it survive extreme heat or cold.
Most commonly carried by Feverfire Phoenixes, spread to cities or townships.
For the first hour it is asymptomatic, though it is spreadable just minutes after you come in contact with it. After the first hour, you begin to experience full-body pains and irritated skin, and a rash begins cropping up on the neck, armpits, crotch, and kneepits. After six or so hours the rash turns to swelling, and sores begin popping up on the rest of the body. Patients report extreme spikes of nervous energy around this time as well, and a fever begins to set in. After twelve hours, the fever will progress to causing delirium, and the patient begins to express a bloody, phlegmy cough. By sixteen hours, the patient will grow nauseous, and vomiting will contain mostly blood. Many will perish in the next four hours from their swelling cutting off oxygen, and they are the lucky ones. The plague kills almost everyone within forty eight hours as their skin finally ruptures and their rotted organs turn to goo.
Contracting the Phoenix Plague, if you do not have a magical panacea, will always kill.
There is no known cure. Towns which are visited by a Feverfire Phoenix are typically rapidly quarantined and burnt to the ground. Magical panaceas and theoretically a Truth related to the disease can cure it, but if one cannot access these within twelve hours, it is better to instead give the patient a merciful death, preferably from afar.