O que Arde ("Lo que Arde" in Spanish, "What It Burns" in English) is a rural drama that follows Amador, a forty-something arsonist who is free from jail after to accomplish two-thirds of his imprisonment to burn an entire mount. Not having friends, money or other resources, Amador returns his natal home in an undetermined so-small mountain town located in the province of Lugo (Galicia; northwest to Spain), living with his aging mother Benedicta. Quiet, calm and man of few words, Amador bears silently the mock of the some neighbors whose don't forgot his misdemeanor by the fire he caused, while tries to redirect his life caring the livestock of the farm and interesting about Elena, town's veterinarian. At the same time, a worried Benedicta talks Inazio, who is restoring ancient ruined houses to turn them in rural resorts for tourists, looking for a job for Amador, in the hope that her beloved son can at least to have a normal life. But the peaceful life of the town dominated by the bad weather of rain and fog ends abruptly when a new fire lights in the mount close to it, threatening not only houses of the town, but neighbors.