The title of the second Harry Potter book is "Harry Potter and the Chamber of Secrets." Released in 1998, this sequel continues the journey of Harry Potter as he returns to Hogwarts School of Witchcraft and Wizardry for his second year. In this installment, Harry uncovers the mystery behind a series of troubling events linked to a hidden chamber within the school, leading to danger for students. The book explores themes of friendship, bravery, and the battle against prejudice, expanding on the wizarding world introduced in the first book. It deepens the characters' relationships and sets the stage for future conflicts in the series.