Mouch and Ritter work together to solve a murder mystery. Severide and Cruz tackle a food truck fire. Gallo goes to see Hawkins about Violet.

The Flash gets an assist from XS. Meanwhile, CCPD enlists Chester for help when a mysterious device is found at a crime scene.

Jimmy runs through the results of some little-known polls in Tonight Show Polls, then catches up with Tim McGraw and Maisie Williams before enjoying a musical performance from Doechii.