Twelve-year-old Ollie is struggling to get by as an orphan in 1871 Chicago. He finds work as a servant for the wealthy Burnham family, including caring for five-year-old Leo Burnham. But Ollie has a little sister of his own—Eliza. Ollie saves every penny he can to someday get Eliza out of an orphan asylum and support them both. Then a massive fire breaks out in the city, and chaos descends. Suddenly Ollie must not only escape the burning city with little Leo, but he must find his lost sister among the wreckage as well. Will Ollie's wits and bravery be enough to save the Burnham's son and his own sister?