The year is 1773, and the tensions between the colonists and the British are heating up. For ten-year-old Silence, the tensions at home are running high as well. All Silence wants is a chance to call Lily—a beautiful snow-white mare—her own. But Silence's father does not think it fitting for a young girl to spend so much time out riding and being reckless. In the days leading up to the Boston Tea Party, Silence learns that someone has been taking Lily out to secret meetings under the cover of darkness. If she doesn't do something drastic, she may lose Lily forever.