The Outskirts: The Crystal Keepers (Jace x OC) BOOK 3

Kendal Anderson still can't believe the way her
life has turned inside out. Stuck in a strange land far from home, she has found her friend Dalton and has survived the first two kingdoms of the Outskirts, but none of that has prepared her for the magnetic highways and robotic bounty hunters of Zeropolis.
Ruled by Abram Trench, who stayed loyal to the evil High King, the government of Zeropolis uses advanced technologies to keep tight control. Luckily, the resistance in Zeropolis is anchored by the Crystal Keepers-a group of young rebels with unique weapons.
On the run from the High King's secret police, Kendal, Cole, and Dalton hope to find more of their lost friends and help Mira locate her sister Constance. But time is running out for Kendal to uncover the secrets behind the Zeropolitan government and unravel the mystery of who helped the High King steal his daughters powers.

*Disclaimer: I do not own any of the characters beside Kendal and her relationship to Jace. All other credit goes to the amazing author, Brandon Mull.