Arthur Parnassus's difficult past, long kept secret from his loved ones, comes to light with the arrival of a new resident on Marsyas. The book explores how the past can influence the present and whether it's possible to break free from past trauma.

The residents of Marsyas are more than just a group of people with magical abilities – they are a family. Arthur and Linus have created a loving home where every child finds security and acceptance, and they must learn to stand together when their family faces challenges.

Many children at Marsyas have experienced exclusion and rejection for being different. The home offers them a place where they can feel safe and accepted, highlighting the importance of finding somewhere to belong and be one's true self without fear of discrimination.