The book is an epistolary novel, narrated in the first person via letters and diary extracts from various characters, but mainly Rupert. The initial sections, leading up to the reading of the uncle's will, told by other characters, suggest that Rupert is the black sheep of the family, and the conditions of having to live in the castle in the Blue Mountains for a year before he can permanently inherit the unexpectedly large million-pound estate suggest the uncle is somehow testing the heir.