When Alex, a waiter and aspiring musician, meets a mysterious singer named Mara his life is changed forever. Not only does he fall in love with her, but soon after they meet he is attacked by a strange creature and becomes one of the Nephilim, the Sons of God known in modern times as vampires. To make matters worse Mara disappears. Now, fueled by his need to find her, Alex must confront the various vampires of Chicago and a secret organization known as "The Tower." If Alex wishes to find her he will have to master the abilities of his new state and come to terms with his inner struggle between virtue and sin.