Eff was born the thirteenth child. She grew up hearing stories about how the "Thirteenth Child" is supposed to have great talent but bring great danger and despair to everyone around her.
Her twin, Lan, is the seventh son of a seventh son, or a double-seven, and is supposed to have great magical talent, in a good way, and luck that makes everyone in awe of him.
This story tells of their growing up, from Eff's point of view, and the challenges they face.
This story started off really well. I loved reading about Eff, Lan, and their magic. I liked reading about how they grew up and how much magic was involved in their lives. But then towards the end it started talking about these bugs that sucked up the magic, and that was the whole plot of the story at the end.
It kind of turned me off to the story, but overall it was well-written and something different in the YA fantasy world.