In a massive fire at a club, Battalion 25 and other units face a challenging rescue operation. With multiple people trapped inside, including police officer Al Olinsky's daughter Lexi, the teams navigate a chaotic interior to save lives. Herrmann's group conducts a primary search, while Casey oversees the outside area. Amidst the intense rescue, a balcony collapses, injuring Mouch. The situation escalates as Lexi is critically injured. Post-rescue, evidence of arson is found, and property owner Barry Kimball, overwhelmed by guilt, takes his own life. The episode underscores the emotional and physical demands on first responders in crisis.