Hunted by Kevin Hearne

Hunted, book six in Kevin Hearne's The Iron Druid Chronicles, begins with Atticus, Granuaile and Oberon in a race to find an open portal to the Tuatha De Danann plain of existence, while avoiding the vengeful grasp of the goddesses of the hunt, Artemis and Diana as well as other assorted members of the Greek and Roman pantheons.

Along with staying out of the path of all the beings who want to kill him, Atticus must also keep Loki (who is free to cause mischief since Thor is dead) from unleashing the Norse apocalypse: Ragnarok. Even with the challenges and enemies Atticus and his friends must deal with through the story, there are Hearn's signature moments of humor and action-packed adventure. As a bonus to the book, there is a novella at the end called Two Ravens and One Crow, which covers some of the back history between books four and five.

 If you haven't read the other books in the series, here's the reading order for the first five: Hounded, Hexed, Hammered, Tricked,and Trapped.