Let me say right off the bat that if you are after a light, straightforward story you can skim through using half your attention, Geoffrey's Queen is probably not for you. The novel is written wholly in the epistolary style, using the diary entries of the two main characters to tell a twisting tale of time travel and inter-dimensional intrigue that spans modern-day Chicago and Colorado, as well as the mysterious land of Kaveg, where two moons grace the night sky and the mountains are actually huge, sleeping dragons.
There's a hint of The Time Traveler's Wife here in the star-crossed romance between the two leads, which makes it necessary to trust in the author's eventual ability to tie together the disparate threads into a cohesive tapestry by the end of the book. In this regard, Gwendolyn Druyor succeeds admirably, and the final quarter of the book is rich with "A-ha!" and "Oh, wow!" moments as the puzzle pieces begin to fall into place. The ending is satisfying but makes it very obvious that more is to come in the series... not a cliffhanger by any means, but rather open-ended.
Well worth a read for lovers of fantasy, dragons, and strong female protagonists.