Firehouse 51 is a cohesive team of Chicago firefighters, rescuers, and paramedics who save lives daily and nightly from the clutches of the fiery elements. Lieutenant Matthew Casey is a born leader and a true firefighter. After breaking up with his beloved woman, he reevaluated his views on many things. And after the death of his friend and colleague Andrew Darden, Casey is now constantly in conflict with another team member - rescuer, Lieutenant Kelly Severide. They cannot come to terms with the loss of their friend and therefore blame each other for Darden's death. The team also includes a rookie named Peter Mills, whose father was also a firefighter, two paramedics: Gabriela Dawson and Leslie Shay, and the chief - Wallace Boden. Being on the front line of life and death, they have to make tough decisions and constantly risk their lives, relying only on the support of colleagues and friends, no matter what happens...