Ambitious young cops try to prove themselves in their high-stakes careers, in which the smallest mistake can have deadly consequences. At the core of the close-knit group is perfectionist Andy McNally (Missy Peregrym), who, along with her friends Dov Epstein, Gail Peck, Traci Nash, Chris Diaz — and of course, her on- and off-again love Sam Swarek — experiences the trials, triumphs and tribulations of police work, as well as its effect on their personal lives.