In the series premiere, Teresa Colvin, Chicago’s city’s first female superintendent, lobbies for a city corruption task force to investigate city politician Alderman Ronin Gibbons. Meanwhile, Colvin’s ex-partner and larger-than-life veteran of the Chicago Police Department, Jarek Wysocki investigates a suspicious murder in Grant Park alongside his new partner, Caleb Evers. Also in Jarek’s charge are his niece, Vonda Wysocki; her hotshot partner, Isaac Joiner; and low-life Liam Hennessey, an Irish thug who blends in with the gritty world of local crime. Together, these cops stop at nothing navigating the Windy City’s underbelly to fight crime and bring down Alderman Gibbons’ empire of corruption.

Following the shocking events related to a fallen officer, Teresa and Jarek vow to bring whoever is responsible to justice. In the meantime, Alderman Gibbons pays a visit to the victim’s family to offer his condolences and plant a few seeds of betrayal, implicating members of the Chicago Police Department. As every officer in the city hits the streets to avenge this cop killer, Jarek and Caleb follow up on some of Liam’s leads, while Vonda and Isaac are promoted to the organized-crime task force.