The basic storyline follows a love story between members of two different worlds that are at war. Alana is a soldier of the planet Landfall, and Marko is a "conscientious objector" from its enemy world, Wreath. The two fall in love while Marko is a prisoner in a Landfall detention center, and the two flee together. While on the run, Alana gives birth to a child, perhaps the first child ever who is born to parents of warring worlds.
The story is rich with political parallels to our own world, like the state of perpetual war between opposing powers, and how that war is "outsourced" to other worlds. There are independent contractors, aristocracy, politicians, dissidents, shady businessmen, a subversive/reclusive novelist, etc. It's a fully realized world that is beautifully drawn and written.
The narrator of the story is Hazel, the child of Marko and Alana, who seems to be telling the story in retrospect. So far, because the story is unfinished, we don't know what happens to Hazel, except that she lives. This gives the reader hope, because Marko and Alana are constantly on the run from bounty hunters and soldiers. Apparently, their love-child is a political liability.
There are all kinds of awesome characters, like the robot prince, the six-legged bounty hunter The Stalk, a truth-telling feline named "Lying Cat," and of course Alana and Marko. They look like humans, but Alana has wings, and Marko has horns and can do magic. He is also pretty badass with a sword. Anyway, I don't want to give away too much (maybe I already have), but I highly recommend "Saga." Thought-provoking and entertaining.