Breaking the Dark finds private eye and retired superhero Jessica Jones investigating the case of a pair of twins who have undergone a mysterious transformation. The first book in the Marvel Crime series, it introduces a street-level side of the Marvel Universe, with the series continuing with original novels featuring characters like Luke Cage, written by S. A. Cosby, and Daredevil, written by Alex Segura.

Jessica Jones is a private investigator and retired super hero based out of Hell's Kitchen, Manhattan, who goes from job to job as a loner. When a wealthy Upper East Side woman named Amber Randall pays her a visit, she expresses concern about her twin sixteen-year-olds, Lark and Fox, who have acted and looked different since they returned from spending the summer with their father in the UK. She tells Jessica that her children have unnaturally perfect skin and have lost the tics and habits that made them who they were. She tells Jessica that something has happened to them.

To find out more, Jessica travels to Essex to talk to their father and meets Belle, who is living an isolated existence in a run-down farmhouse with her guardian Debra. Jessica knows that Lark and Fox spent the summer with Belle—but can this teenager be responsible for Lark and Fox's new personas? Jessica soon discovers that, behind Belle and Debra, geniuses are playing a game with technology in order to make the world a 'better place', not caring who gets hurt, maimed or killed in the process. Can Jessica stop them from wreaking destruction on a generation of young people?