Scrappy Maisie McGrane is desperate to join her Irish family's cop fraternity. The youngest of six siblings (and the only girl), she is on track to graduate from the police academy as top cadet just like her brothers...until she gets expelled after she fails her psych evaluation. So she takes a job as one of the most universally loathed public servants in Chicago: parking enforcement agent, a.k.a. meter maid, in order to prove she isn't "too thin-skinned to deal with a hostile public" and try to finagle her way back into the academy.
When Maisie s discovers a dead mayoral staffer in a parked car, her badge-wielding older brothers warn her off the case. However, Maisie is determined to solve the case as a way of proving her worth to the police. With the help of her secret crush, shadowy ex-Army Ranger Hank Bannon, Maisie uncovers a conspiracy of explosive proportions.