Band of Sisters
The Way into Magic (The Great Way, volume 2)
By Harry Connolly
When last we saw our heroes, monsters from another dimension had swarmed out of an inter-dimensional gateway to overwhelm the Morning City and then the Peradaini empire (of which the Morning City had been the capital). As the cast of characters dwindled rapidly (in a way that those of us with crappy memories appreciate) the survivors have gained a realistic understanding of their situation.
The empire is dead, although parts of it remain unconquered by the invaders. But it gets worse.