The The Twelve Tasks of Flavia Gemina: Book 6 by Caroline Lawrence
Mystery and adventure for four young detectives in Ancient Roman times . . .
Flavia is suspicious of the new woman in her father's life, Cartilia Poplica. She's certain that Cartilia has an ulterior motive, but to find out the truth Flavia must perform twelve tasks - like the Greek hero Hercules.
So begins a thrilling journey, but what will Flavia learn at the end of her quest?