Every other day, Kali is a normal sixteen-year-old girl. She goes to high school. She attends pep rallies (even though she tries to stay invisible). She's human. But every day in between... she's something else entirely. Though she looks the same, predatory instincts take over and Kali becomes a feared demon hunter with the urge to hunt, trap, and kill zombies, hellhounds, and other creatures. She doesn't know why she's the way she is, but she gives into instinct anyways. Even though the government considers it environmental terrorism. When Kali notices a mark on a popular girl at school, she knows the girl is marked for death. She's got 24 hours to save the girl, and she has to do it as a human. With the help of a few new friends, Kali takes a risk her human body might not survive... and learns the secrets of her mysterious condition.Intriguing and fast-paced, Jennifer Lynn Barnes presents us with Kali, a shy part-time teenager part-time demon hunter with a hero complex, needing to protect everyone and hunt monsters on her demon days and hiding as much as she can from the monsters on her human days. When her world turns upside-down, she learns the reason why she's not like other girls, and that she's not alone.A very interesting premise. Kali is still the same person, still has the same thoughts and does the same things, but on those days when she's a demon hunter she's a little more reckless, possibly because she's invincible, and as she puts it, bulletproof.I was surprised as how quickly the book moves along. Barnes wasted no time getting right into the story, right into Kali hunting hellhounds, right into her normal day at a pep rally, right into seeing the mark that could kill one of the popular girls. No fuss, no muss, which is awesome. No unnecessary info-dumping at the beginning and no walking in blind. Just the right mix of showing and telling, of Kali's internal perceptions of the world around her and classmates being totally not what she expected.I'm noticing a trend of strong teen girl characters, ones who know how to fight and take a punch and carry knifes hidden in boots or clothes or even hair. Look at Tera Lynn Childs' Sweet Venom (Gretchen), Moira Young's Blood Red Road (Saba, sort of, she does know how to fight and how to survive), Richelle Mead's Vampire Academy (Rose), and my personal favourite, Lili St. Crow's Strange Angels (Dru, I have so much love for Dru). This isn't bad, we need to empower girls at a young age to make them strong, as strong as boys, possibly stronger, but demon hunting doesn't often pop up in real life.And Kali was unique, both strong but also meek, so knowledgeable about zombies and hellhounds but needing to keep to the edge of everything, to stay unnoticed.Fans of Jennifer Lynn Barnes' Raised by Wolves series will reach for this book with open arms and happily devour it, relishing the thought of another strong teen girl character attempting to navigate a very complex world.