This book is about Marco Loristan, his father, and his friend, a street urchin named The Rat. Marco's father, Stefan, is a Samavian patriot working to overthrow the cruel dictatorship in the kingdom of Samavia. Marco and his father come to London where Marco strikes up a friendship with a crippled street urchin known as The Rat. The friendship occurs when Marco overhears The Rat shouting in military form. Marco discovers he had stumbled upon a strangely militia-like club known as the Squad.