Ava Goldhawk used to think her life lacked adventure. When she agrees to attend a military ball with her brother, Jared, however, everything changes. There, she makes the acquaintance of mysterious, charming Callias Varela. Ava is very taken with Cal and gives him her number before leaving the dance-but as she leaves, she is hit by a car. As she lies dying on the pavement, Cal-who, it turns out, is member of the species that humans call vampires-gives her his blood and saves her life. When she awakens, she is like him. These creatures, recently revealed to society, are nothing like Bram Stoker's vision. In fact, they aren't even from Earth; they come from another planet, and Ava has no idea how long they've been here or why they've come. Cal's connection to Ava is more than just immortal creator; they develop an intense romantic relationship as well, and she has never felt safer with a man. In an effort to learn more of the origins of her new species, Ava travels with Cal and her brother to the Andes Mountains. Answers await there-but so does an unforeseen danger that threatens their lives.