After the events of The Goddess Test, Kate is on her six-month sabbatical from the Underworld, and has decided to vacation in Greece with her best friend James (aka Hermes). However, James drops her smack dab in the middle of a millennia-old feud between Castor and Pollux, the Gemini twins, and the gods of the council, which occurred when Pollux broke Castor out of the Underworld. Kate is a lot more sympathetic to the twins, and decides that she must help them remain together, even though it goes against the ruling of the gods (particularly Hades and Zeus).
Let me first say that I didn't think The Goddess Test was that great of a book. Being a huge fan of the myth of Hades and Persephone - I used the tale as my first telling in my Storytelling class - I had major issues with the way the mythology was used, and the "tasks" (for lack of a better word) that Kate had to accomplish in order to become Henry's wife. Some of these same issues are alive and well in The Goddess Hunt, and will most likely be present for the remainder of the series. However, I liked this novella well enough, especially the chapters from Henry's point of view, that I'm going to rate it exactly as I did The Goddess Test. There were some definite things I didn't like - again, with the inconsistency of her mythology - but I will say that Kate was pretty awesome in standing up to Walter. She's got a definite backbone, even if I can't always stand her decision-making.
Also, just a note: this isn't a stand alone story. If you haven't read The Goddess Test this won't make much sense. Just an fyi!