River's Edge (The River Immortals, #1)

“Does salvation have a number? How many lives must I save before I’m redeemed?” 

Eighteen-year-old Kasia Maier planned to spend her summer studying turtles in the sand prairie, not trudging through fearsome backwaters with her new coworker, Blayne. And when a monster drags Blayne into the Mississippi River, Kasia never expected herself to jump in after him. She saves him, but soon she’s discovering the monstrous in other places . . . including herself. Now she’s wavering on the edge between a dwindling humanity and a dreadful immortality. The river is tempting one moment, terrifying the next. She doesn’t understand who she is or where she belongs. Blayne, the one person with the potential to help her, is also the hardest to resist. If she can’t stop her own transformation into a river spirit, he will be her first victim. And that's just the beginning—even greater threats are lurking in the shadows.

Combining the Illinois setting of Thomson Causeway and the scariest of Slavic mythology, RIVER’S EDGE will make you question everything you know about nature, evil, and redemption.