In DARK: Olivia's Journey, the second book of The DARK Series, Nathan sets out on an adventure with his new found ally, Olivia. She is a soldier in an elite military force known as DARK and has just lost her whole team to cannibals. Olivia needs to get back to her base and Nathan suspects his missing family may be taking shelter there, as well. As they make their way to the base, they discover that there are many complications and obstacles along the way.