Darkness Unbound (Dark Angels, #1)

From Book 1: Born from a lab-enhanced clone mother and an Aedh father, Risa Jones can not only talk to the souls of the dying and the dead, but she can see reapers and walk the grey fields that divide this world from the next. They are skills she rarely uses, however. But when her mother asks her to help the parents of a little girl locked in a coma, she reluctantly agrees. What she discovers terrifies her: someone has ripped the girl's soul from her flesh. As it turns out, a creature consuming the souls of the innocent - and not so innocent - is the least of her problems. Because someone wants to rip open the gates that divide hell from earth, and Risa is a key component in their plans. And the only person standing between her and disaster is a reaper who isn't exactly on her side.