Firehouse 51 is on high alert when a series of explosions rock the city. Herrmann adjusts to his new duties and Kidd gets a visit from an old friend.
Chief Boden becomes increasingly skeptical of Assistant Deputy Commissioner Gorsch’s motives, while Severide gets wrapped up in a difficult situation following the rescue of a child from a car wreck. Trying to fit in with the rest of the firehouse, Foster is tasked with doling out some personal advice to Cruz.
In the first part of a three-show, one-night crossover event, Firehouse 51 is faced with a daunting challenge when an out-of-control blaze consumes a 15-story apartment complex, trapping victims on the top floors. Complicating the rapidly escalating situation, members soon discover that someone close to home may be one of the trapped victims.
Casey tries to deal with his unsettled personal life and the firehouse welcomes a new member. Boden clashes with new Assistant Deputy Commissioner Jerry Gorsch.