Wayfinder

THE TRUTH WILL SET YOU FREE--IF IT DOESN'T KILL YOU FIRST
Lara Jansen is a truthseeker, gifted--or cursed--with the magical ability to tell honesty from lies. Once she was a tailor in Boston, but now she has crossed from Earth to the Barrow-lands, a Faerie world embroiled in a bloody civil war between Seelie and Unseelie. Armed with an enchanted and malevolent staff which seeks to bend her to its dark will, and thrust into a deadly realm where it's hard to distinguish friend from foe, Lara is sure of one thing: her love for Dafydd ap Caerwyn, the Faerie prince who sought her help in solving a royal murder and dousing the flames of war before they consumed the Barrow-lands.
But now Dafydd is missing, perhaps dead, and the Barrow-lands are closer than ever to a final conflagration. Lara has no other choice: she must harness the potent but perilous magic of the staff and her own truthseeking talents, blazing a path to a long-forgotten truth--a truth with the power to save the Barrow-lands or destroy them. "From the Trade Paperback edition."