Dark Descent (Nyx Fortuna #2) by Marlene Perez

The second in a line of three exciting new urban fantasy novels where the son of the Fates must travel to the underworld...

Nyx Fortuna is still reeling from Elizabeth's betrayal, but Nyx's cousin, Claire, has run away, and he has to find her and bring her back, or Elizabeth will suffer at the hands of his aunts, the three Fates. Claire has gone into the underworld of Minneapolis, where no one, not even the Fates, can follow. But Nyx must journey to a place where Hecate's dark magic has Claire in her thrall. Saving his cousin means releasing Hecate from her underworld prison and perhaps fulfilling the prophesy foretelling the Fates.