Series Two jumps straight in at the deep end with an explosive season opener. Having learnt of the existence of a mole in Station 19, Ben Chartier reluctantly agrees to spy on the squad and prime suspect Nick Barron. Their quiet shift takes a dramatic turn when they are first responders to what proves to be the worst call of their careers. With the entire squad involved, the fallout from the tragedy has a devastating impact as they struggle to come to terms with what has happened. Linked to the deaths of at least three police officers, the race to discover the mole's identity gathers pace. Following a lead of their own Nick and his cousin Kaz get in far too deep. Audrey returns to active duty and although her physical beauty is restored she is still badly damaged on the inside. J.M. faces his inner demons and Tyler is forced to confront his fears. All of which pushes partnerships and ultimately the squad to breaking point. A gritty, hard hitting drama where the team is defined by their scars both old and new, 19-2 examines what the uniform does to those who wear it.