The tainted city (#2) : Shattered sigil
(Book)

Dev is a desperate man. After narrowly surviving a smuggling job gone wrong, he's now a prisoner of the Alathian Council, held hostage to ensure his friend Kiran - former apprentice to one of the most ruthless mages alive - does their bidding. But Kiran isn't Dev's only concern. Back in his home city of Ninavel, the child he once swore to protect faces a terrible fate if he can't reach her in time, and the days are fast slipping away. So when the Council offers Dev freedom in exchange for his and Kiran's assistance in a clandestine mission to Ninavel, he can't refuse, no matter howmuch he distrusts their motives.--from pubisher's description.