Twelve-year-old Elias is sent to Mammoth Cave in Kentucky to fight a case of consumption--and ends up fighting for the lives of a secret community of escaped slaves traveling along the Underground Railroad.

Having Poppa home fills Addy's heart with happiness, and moving to a boarding house brings a new special friend--one who encourages Addy to always stay hopeful for the future. Then Addy enjoys the victory of having her idea chosen for a fair fundraiser, where a friendship is born, and the answer to a riddle brings a wonderful surprise. But will the rest of Addy's family be reunited before the New Year?