Sally Green 
Demon World (The Smoke Thieves Book 2) 

The second book in The Smoke Thieves series from Sally Green – perfect for fans of Leigh Bardugo and Game of Thrones.Scattered by the tides of war, Princess Catherine leads a ragtag band of survivors into the barren wasteland of the Northern Plateau.With enemies snapping at their heels, they are driven into the strange and deadly tunnels of the demon world. But while Tash dares to go deeper, Catherine must return to the surface to confront a nation in turmoil – and her growing love for Ambrose. On the run from the law, Edyon and March grow closer even as their secrets threaten to tear them apart.Under attack from all sides, truth becomes the first casualty. But as their deceptions multiply, will the Smoke Thieves‘ lies save them or bring disaster?