City of Broken Magic

Mirah Bolender's fast-paced, adventure fantasy debut, City of Broken Magic, features a bomb squad that defuses magic weapons.

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Five hundred years ago, magi created a weapon they couldn't control. An infestation that ate magic—and anything else it came into contact with. Enemies and allies were equally filling.
Only an elite team of non-magical humans, known as sweepers, can defuse and dispose of infestations before they spread. Most die before they finish training.
Laura, a new team member, has stayed alive longer than most. Now, she's the last—and only—sweeper standing between the city and a massive infestation.