Ex Heroes by Peter Clines

In a post-apocalyptic world where superheroes and zombies coexist, a group of heroes known as the "Exes" strive to protect the last remnants of humanity in a fortified community called the Mount, located in Los Angeles. As they battle the undead and grapple with their own personal struggles, the heroes face a new threat from a mysterious figure who controls a rival group of super-powered individuals. The story weaves together action, suspense, and the complexities of heroism as the characters confront both external dangers and their own inner demons to ensure the survival of their community.