Andy McNally’s first shift on the job turns into mayhem when shots are fired in a downtown rooming house. In the midst of the chaos, Andy triumphantly makes her first big arrest – a suspected drug dealer – who turns out to be Sam Swarek, an undercover officer from her own division. She makes up for her grave mistake by going face to face with a dangerous gunman who already has one man’s blood on his hands.

A severe heat wave wreaks havoc on the city, forcing the rookies to work around the clock to keep the peace. In the midst of the chaos, Andy discovers that a serial rapist may have resurfaced to prey on vulnerable teenage girls. And when the extreme temperature precipitates a citywide blackout, Andy finds she’s cut off from all backup and must take.