Lauren Dane, a gateweaver, travels back and forth between Earth and Oria. Her parents erased her mind when she was a child and she is re-learning how to travel back and forth...and why she should or shouldn't.
Molly McColl, a healer of epic proportions, is a hybrid alien/human who is kidnapped by Orians and foribly returned to Oria as their savior.
On Oria, humans have spectacular magical abilities, however, magic used on the alien planet adversely affects Earth. The sentinels are tasked with protecting humans from the feedback of this magical usage. Eric is the leader of the Sentinels and he works with Lauren, as well as the other Sentinels to figure out how a plague on Earth was started and how to contain it.
This is an extremely complex world with numerous dangers and challenges facing all the characers...both the good and the evil ones. I enjoyed the layering of the foundation and the dissection of the characters. I especially enjoyed Lauren and Molly's adventures.