The team has to try and stop serial arsonist Leonard Brooks after he starts to use fire as a weapon to hurt people from his dark past.
The team leads an investigation when a fire chief, a friend of Mac, ends up dead in a blaze that used the same technique as a recently paroled arsonist.
After a strange odor causes a captain of a women's roller derby team to collaps on the track, she seeks Dani's help. Meanwhile, Marshall Pittman takes charge of the Hawks and threatens to let TK go who is still dealing with the aftermath of the shooting.moreless
There are dire consequences when Charlie messes up some calculations during a case and his brother is injured as a result.
The team enters the world of sneaker collectors after a foreign ambassador's vault is broken into and a limited edition pair of sneakers is found missing.