Two brothers, Stephen and Brian McCaffrey, follow in their late father's footsteps by battling blazes in the Chicago Fire Department. Stephen, a seasoned and valorous firefighter, is critical of his younger brother Brian's inability to commit, which leads to a falling out after a dangerous incident. Years later, Brian rejoins the department, eager to prove his worth, but the tension between the siblings runs high. Meanwhile, the city is plagued by a series of deadly fires that seem to have a sinister cause. Brian, assigned to assist in the investigation, is met with skepticism due to his rocky history but is determined to uncover the truth.

As the investigation deepens, the brothers are forced to confront their personal demons and the legacy of their father's death. The trail of clues leads them to suspect arson, and the hunt for the firestarter becomes a pressing race against time. In tandem, Brian must navigate the complexities of his relationship with Stephen and the shared trauma of their past. With each new blaze, the tension rises, not just within the fire department but also within the city as the citizens fear for their safety. The pursuit of the arsonist pushes both brothers to their limits, as they must work together despite their differences to stop the menacing inferno before it claims more lives.