Atwater's reactions during a tense arrest are called into question. The team must dig in to uncover key evidence that could aid in the ongoing investigation and clear Atwater's name.

In an attempt to distract Intelligence from the investigation into his son, Chief O'Neal forces Voight and the team to handle a "dead fish case." However, when that dead fish turns into a complicated heater case, Burgess is thrown back into difficult memories from her past.