Massachusetts, 1854. The anti-foreigner American Party, better known as the “Know-Nothings,” take power throughout the state. The city of Lowell elects Leonard Ward, a member of the party, as its mayor. Suddenly the “Know-Nothings” are everywhere. And they’re going after the Irish. Rosaleen is ready to fight back. Emboldened by strange conspiracies about the Catholic Church, violent mobs and corrupt government officials are making life nearly unbearable for her people. Lowell’s newly formed police department is committed to ridding the streets of “Irish filth,” beating and arresting anyone who crosses them. When Rosaleen uncovers a horrific truth, it will test her in ways she could never have imagined. Targeted by dangerous opposition, she needs help. But are her friends as loyal as she believes?