Three Parts Dead by Max Gladstone
Kos the Everburning is dead. The patron god of the city of Alt Columb, who’s divine power provides heat and power not only for the citizens of his chosen city but for countless other cities and nations beside has died and something must be done about it. To that end the Church of Kos has brought in two necromancers (partner in the firm Elayne Kevarian and very junior associate Tara Abernathy) from the international Craft firm of Kelethras, Albrecht, and Ao to find a solution to bring back Kos or scavenge what remains of his divine power while staving off his spiritual creditors.
But the circumstances of Kos’ death are not clear and the tangle of obligations that surrounded the god and his Church even less so. Tara and Elayne are under a tight schedule, however for Kos provided much to many in Alt Columb and beyond and it will not take long before everything he supported will start to fall apart.