In the peaceful English countryside of 1859, fifteen-year-old Mark Apperley is bored of life with his overbearing grandmother. His plan to escape brings about dramatic results: he is sent away to the heart of revolutionary Europe. On a journey to Rome, he meets Tessa and Pietro, two young revolutionaries, and soon he sneaks away from his classics lessons to join the Student Corps, and embarks on an expedition with a hero wearing a black-plumed hat - General Garibaldi himself.