Escarcha como noche (Frost Like Night, last book of the Snow Like Ashes trilogy)

Angra is alive and his Decay is spreading. Meira desperately needs to learn to control her own magic—so when the leader of a mysterious Order from Paisly offers to teach her, she jumps at the chance.  But the true solution to stopping the Decay lies in a labyrinth deep beneath the Season Kingdoms. To defeat Angra, Meira will have to enter the labyrinth, destroy the very magic she’s learning to control—and make the biggest sacrifice of all. 

 Author: Sara Raasch.

 Translator: Nora Escoms.