City of Loons. The Walls of Orion duology

There aren't many places to run in a city surrounded by a wall. Courtney Spencer has left her safe, normal life behind. Joining up with Orion City's #1 Most Wanted man, she plunges headfirst into an underworld she never knew existed-a realm full of Changers, like herself, willing to do whatever it takes to bring Orion's darkest shadows into the light of day. But W's plan for justice may reach further than she's willing to go.
With a murderous organization on their heels, and her detective ex-boyfriend not far behind, Courtney must rely on dangerous new friends to bring down AITO and the Wall once and for all. But when using her newfound ability means risking her own sanity, and her ties to W put her in danger of falling in more ways than one, Courtney will need to fight to become someone who can bring true justice-without losing herself, or her heart, in the process.
Packed with suspense, heart-pounding action, and forbidden romance, this thrilling conclusion to The Walls of Orion duology tests the boundaries between villain and hero, revenge and revolution, and raises poignant questions for a world not so far-off from the world within the Wall.