Burn for Me by Ilona Andrews

In this spellbinding first novel in #1 New York Times bestselling author Ilona Andrews's urban fantasy Hidden Legacy series, private detective Nevada Baylor navigates her way through an alternate world where dynasties, built on inherited wealth and magic, guide the course of humanity.
?Nevada Baylor runs a small-time detective agency in Houston, Texas, busting scammers, exposing cheaters, and dealing with petty criminals. She's very good at her job-helped by a magical ability to sense when someone tells the truth or lies. But when she's forced into accepting a case to find a radical pyrotechnic who can conjure heat and fire at will, Nevada knows she's out of her league. To bring him to justice, she'll have to join forces with someone who wields an even more dangerous power.
Connor "Mad" Rogan is a former combat mage, a telekinetic singularly responsible for mass destruction in war-torn countries, and a member of one of the most powerful magic families in the world. His nephew has been kidnapped by the fugitive pyromaniac, and Nevada is his best chance at finding them both. But unlike Nevada, Connor could care less about societal law and order, and has no qualms about extinguishing his family's enemy.
Bound by their mission, Nevada and Connor clash over their tactics and moral beliefs, even as things undeniably heat up between them. But the man they're chasing is involved in a darker conspiracy that threatens to destroy the city-and destabilize the balance of power the elite magical families use to influence every nation on Earth.