Gibbs and Ducky suspect that an antique war stick seen on television may be a missing murder weapon linked to an unsolved case from 16 years prior.
Casey reunites with a former colleague; Dawson and Brett serve their time in retraining; Severide tries to fix what's going on with Anna.
After a teenage girl makes a rape accusation against a person with a criminal record, but little evidence is found, the girl's father takes matters into his own hands.
Devon pushes Bell to take drastic measures when a mother's complaints go unaddressed after her delivery; Conrad tells Nic about Jessie's worsening condition; a mother and son appear with devastating injuries.
A warehouse blaze puts the fire and rescue squad at risk; Dawson's father overstays his welcome at Dawson and Casey's home; Casey fights for his first responders bill; Mouch makes a serious decision; Herrmann tries to make a young boy smile.