It is 1845 and eighteen-year-old Liam Reilly has no idea that his world is about to be shattered. He cherishes County Mayo with its beauty and close family even though life is hard. As tenants, the Reilly family grows grain to pay high rent to the English landlord while they eat mainly potatoes. He and other Irish are not aware that for the last twenty years, the British government has been urging landlords to evict tenants in order to provide pastures for ranching. It wants Ireland to produce fresh meat and get grain from more distant colonies like British Canada. Despite this plan, most landlords still have tenants growing grain, but some are starting to evict.
Liam still hopes for rights and a better life, especially when he meets the beautiful Colleen at a wedding in nearby Ballinglass. Terror strikes her village when her landlord razes it to the ground to create pasture! Her family is forced to the dreaded workhouse, and thinking he sees her at a high window, Liam prays she can survive.
To earn passage money to America, friends from Ballinglass go to England. Niall, Liam's older brother, goes with them and when they return, he announces that he too is emigrating. The devastated family plans a Feast of Departure, knowing this goodbye is forever. The music and forced gaiety give way to sorrow as his mother hysterically clings to Niall. Six months pass with no word and the family worries.
A partial blight on potatoes the year before has left many starving and Liam frets as the family shares dwindling supplies with beggars. Turf cutting, harvest, and roof thatching distract Liam until one dawn in August, he hears the door open and Mother's scream. Horrified, he rushes out to plants consumed by fungus. Potatoes everywhere are ruined and starvation spreads.
People gather to write petitions, begging for assistance, but high government officials in London refuse to interfere and send more soldiers to guard convoys taking food to port. Liam and his father risk arrest and organize thousands in a peaceful march to ask their landlord for mercy. Marching home, they pass a convoy of soldiers guarding food being taken to port. Soon after, Liam hears distant shots. Frantic, he realizes his brother Sean is missing as soldiers search the marchers for a wounded lad, trying to take oats.
Trapped in a desperate struggle, the family pulls together with great courage. When Liam kills a swan for Christmas dinner, relatives gather around the table. But he fears Colleen will die in the horrors of the workhouse. As the crisis deepens and the government confiscates their meager goods as tax, the family is pushed to the edge. Liam and his brother face constant danger from guards and soldiers as they scavenge for food and take enormous risks for the sake of the family. Intense conflict and suspense propel the story forward until at the end, Liam must overcome great obstacles if he is to save his mother and sisters. At 10 Downing Street, 1849, government leaders argue while Ireland falls silent.