Carpenter, T: Shadows in Amber - Thomas K. Carpenter - Bog

The two major clans of the Undercity, Razor and Drops, are at a fragile peace after decades of conflict. When Pandora is sent to the Undercity to infiltrate the clans and uncover the source of the faez crystals-unusual gemstones that give Undercity warriors magical abilities allowing them to run up walls or move heavy object with a gesture-she joins the Drops clan after saving the life of its warleader.
Kuma Santos, son of Razor's clan leader, has been training to be a warrior of the Undercity his entire life, but his lineage creates expectations that make him a target for his rivals.
Tensions rise between the clans as young warriors clash on neutral ground to uphold their honor bound ways, bringing together Kuma and Pandora who discover an inconvenient attraction. Conflict turns violent as rumors of a spy send waves of distrust through both clans. With storm clouds on the horizon and control of the
ndercity-and the faez crystal trade-at stake, it'll only take one spark to trigger the war.
Set in the Hundred Hall Universe, the Crystal Halls series is perfect for urban fantasy fans who enjoy epic adventures, fantastic families, and an enemies-to-lovers romance in the shadows of an underground criminal network. Pick up book 1, Shadows in Amber, today!