When multiple people are shot inside an athletic club intelligence work to find and take down the shooters before there's any more victims. When they discover that all the targets were from the same law firm it's apparent that it is a case of corporate revenge. Now they need to find out what the motive for these killings. Atwater is dealing with his new assignment, while doing so he plays a key role in locating the shooters. Meanwhile Platt (Amy Morton) and Halstead are trying to approach Lindsay to see how she's coping with a recent death.