Richie shoots a teenage boy in the line of duty. Meanwhile, Abby works with one of her heroes in a case involving a mob mole.
An ex-con accuses some police officers of harassment. Meanwhile, Abby is propositioned by the detective investigating Richie's shooting of a teen, and Sheila visits the mother of the boy Richie shot in an attempt to cope with her own grief.
Abby and Lina investigate a stripper's murder and discover she was killed at a private cop clubhouse where Don is a member. Meanwhile, Richie learns about Brody and Abby.
Abby and Lina investigate an officer who is accused of stalking his female police psychiatrist. Meanwhile, Richie is partnered with an old family friend who plays fast and loose with the law; and Abby's relationship with Danny heats up.
Abby and Lina investigate 911 response complaints after they are unable to get emergency help. Meanwhile, Donnie tries out for the SWAT team, which leads to family secrets being revealed.
Abby and Lina investigate a model's murder and the case brings to the surface repressed childhood memories for Abby about her dad's struggles with the horrors of police work.
Songs: Billy Idol -- White Wedding (Part 1)
Abby and Lina investigate an undercover Internal Affairs officer posing as a stripper to infiltrate a corrupt cop's inner circle. Meanwhile, Brody gets advice from Abby's mother on how to woo Abby.
Abby and Lina investigate the apparent suicide of a police officer and sexual-abuse allegations against the department chaplain. Meanwhile, Mackie and Abby's brothers plan a surprise birthday party for Abby and argue over whether to invite Danny or Brody.
Songs: Graham Colton -- Love Comes Back Around
Abby and Lina investigate allegations of dangerous hazing at a Chicago police-recruitment academy. Meanwhile, Sheila hires reformed convicts to work at her bakery, but her decision worries Don.