Jimmy's recovery complicates his return to the firehouse as he tries to take on too much, causing discord amongst his fellow firefighters over his all-consuming need to prove his abilities have not been lost. Meanwhile, Alex Taylor joins the firehouse and arrives with some baggage of her own.

Joey starts a fire while on a field trip with his class, causing Kim and Jimmy to reevaluate their parenting styles and inspiring Kim to try to rebuild her family, starting with a reconciliation with Jimmy. But Jimmy's relationship with Brooke is not nearly as wobbly as Kim would like to think, and Kim ends up jumping into bed with a stranger and then commiserating with her mother over her problems with men, ending in a confrontation with Brooke that forces Kim to rethink what's best for Joey in the matter.

The deaths of four teenagers in a fiery car crash profoundly affects the third watch, who were forced to stand by helplessly, unable to save the victims. They congregate at the end of the shift to dispell their sadness and anger at the horrific images of the crash. Faith, Sully and Doc spend time sitting quietly in a cafe; Ty, Bobby, Carlos and Alex go to a bar; and Kim, Bosco and Jimmy go bowling. As evening turns into day, Faith's group meets up with a young woman, Ty's group meets up with a young man, and Kim's group meets up with a young couple in love. At dawn, everyone ends up at the a beach and they build a bonfire. As the flames flicker, we see a flashback to the moments immediately preceding the car crash and discover that the young people whom they met during the course of the evening are the spirits of the teenagers who died in the crash, who were sent back down to earth to tell them that the crash could not have been prevented, and they are not to blame for being unable to

The ordeals of an elderly friend prompt Sully to consider his own loneliness; Alex regrets revealing that she discovered Jimmy on the eve of his wedding having sex with an old flame who happens to be Lombardo's current girlfriend after the news spreads like wildfire throughout the squad; Jimmy and Brooke get married.