Divine Beginnings by P.C. Cast
This was a really cute prequel to the Partholon series. We get to see a bit more about how the Fomorians began their invasion and how they initially sunk their claws into the land. It also lays the groundwork for the vase and antique show - which actually does clear up a handful of questions that I just gave up on from book one.
The romance is very quick. It's a down and dirty novella so there isn't a lot of time for courting here. But it is still a very sweet one that is quite unexpected. The devotion in the relationship is great and I really enjoyed seeing how the whole realm jumping began.