Intelligence is forced to sort through a complicated web of clues surrounding the murder of a mother and her daughter.

Firehouse 51 enlists intelligence to help corner the arsonist they believe killed Shay.

Lindsay thought she'd landed the real estate assignment of her dreams, but what seemed like a golden opportunity turned deadly.

It started out with a couple who seemed made for each other: smart, good looking and in love. But after a secret was uncovered, their passion turned into violence. Then, an elaborate plot to get revenge so twisted and devious, it nearly succeeded.

An Air Force captain is shot dead, leaving police to suspect his wife and her sharpshooter lover.

Nearly 40 years after a high school senior is found stabbed to death in her car after visiting the mall days before Christmas, investigators identify the killer.

Tensions rise when Severide crosses paths with someone from his past.

Dawson puts herself in danger to help her brother.