The squad is called to put out a fire in the local jail, but the situation quickly gets out of control when the power goes out and the squad is trapped inside a prison filling up with smoke. Hermann is grabbed and taken as a hostage, but Casey comes up with some quick thinking to rescue him.
Mills applies to the Chicago PD after being passed over for rescue squad.
A new bar is opening up across from Molly's.
Renee shows up pregnant.