Thanks to NetGalley and Gallery Books for the arc of The Map of Bones by Francesca Haig! The Map of Bones is the second book in The Fire Sermon series. Radiation destroyed the world and created defects and oddities, as well as everyone alive having a twin. The strong twin is the Alpha and the different twin is the Omega. The Omegas are persecuted, but if one twin dies, they both die. Secrets of life after the blast are discovered and the race is on between the council and the resistance to see who gains and uses the knowledge first. Cass has grown wiser through her trials and experiences with others. The suspenseful and interesting world building make this a good read!