The second book in the magical new middle-grade series about an anxious girl who investigates legendary monsters, by the award-winning author of Lenny's Book of Everything and Dragon Skin

There are those who hunt monsters to harm them and there are those who hunt monsters to help them. Which one are you?

Miss Mary-Kate Martin and her mother are off on an adventure to the enchanting Greek island of Galinios. An ancient mosaic has been unearthed and Professor Martin must investigate, leaving Mary-Kate to explore the island and bask in the sunshine.

But soon her relaxing holiday turns into a monster-sized mystery, when a message arrives asking for help. Could the local legend of the Two-Headed Hydra be more than just a story? And what could have made this serene sea creature so angry?

Miss Mary-Kate Martin might be anxious, but she's not scared of monsters! With the help of her new friend Nikos, she is determined to find answers.