The Fifth Season (original) N.K. Jemisin

Three terrible things happen in a single day. Essun, a woman living an ordinary life in a small town, comes home to find that her husband has brutally murdered their son and kidnapped their daughter. Meanwhile, mighty Sanze -- the world-spanning empire whose innovations have been civilization's bedrock for a thousand years -- collapses as most of its citizens are murdered to serve a madman's vengeance. And worst of all, across the heart of the vast continent known as the Stillness, a great red rift has been torn into the heart of the earth, spewing ash enough to darken the sky for years. Or centuries