From its humble beginnings (for a while, the fire-fighting force consisted largely of drunks and vagrants) the service gradually became more professional, developing new techniques and introducing smokejumpers (special teams that parachute into hot spots).
When the Kittredge house is burglarized in a crime wave that the newspapers are blaming on vagrants, the plot becomes a mild mystery that Kit tries to solve for the sake of her young hobo friend Will (Max Thieriot).