Tattered Lands - Barbara Ann Wright - Bog

Humanity thinks itself safe. For over thirty years, ten mystical pylons have protected them from the plague of the evil, tattered lands. Now, one pylon has gone out.
Alchemist Vandra Singh knows an alliance with the elusive, xenophobic seelie may be humanity's only hope if the other pylons fail. But among the long-lived seelie, only Lilani, young daughter of the empress, can forgive humanity's ancient betrayals.
As Vandra and Lilani strive to make peace, they slowly fall in love. With mistrust and murder surrounding them, only their faith in each other can keep their plan to save the world from falling apart. And the tattered lands are waiting. One pylon down. Nine to go.