Invisible Journey — Mary Buckham

The Underworld screws even a good plan and this one didn't start out good. Half-witch/half-shaman Alex Noziak must lead two fellow Invisible Recruit agents deep into the Underworld to track a powerful demon who rules his realm with a bloody fist and has kidnapped a teenage Seer. The team faced this demon leader once before and the result was devastating. Now? The odds are far worse this time. Alex and her team must stop the demon before he forces the Seer to open a portal, which will unleash the Seekers to wreak vengeance on humans and take possession of the mortal world. Everyone faces sacrifice, but this time Alex stands to lose.