All Remaining Warmth Was Escaping (en Inglés) - Chris Tomasini

In 2017, after being lost in time for over a century, fifteen-year-old Agata Obara searches for her sister, Dorota, who vanished into the devastation of south-eastern Poland during the Second World War. But the path to Dorota is bound to the secret history of another sister, Eva, and her desperate war against the magical Kutzer family - a war that leads to young Manfred Kutzer's death march out of Breslau in winter 1945. As history and magic and generations bleed together, Agata's cousin Jeremy struggles with his own awakening gifts, haunted by the feeling that some secrets are safer, if they are allowed to sleep undisturbed in the darkness.

All Remaining Warmth Was Escaping is Book Two of the Douro-Zamość Trilogy.