The Twelve Tasks of Flavia Gemina
Caroline Lawrence
 The novel is set three months after The Dolphins of Laurentum and six months after the children solved their first mystery. The Geminus household is still suffering financially from the loss of the Myrtilla. It is winter AD 79 during the five-day festival of the Saturnalia, a time when the status quo is upset. Ostia is further excited by the escape of some exotic wild animals, possible man-eaters. The children narrowly escape an alarming-looking bird. Flavia is disturbed when her father Marcus starts talking about her betrothal and insisting that she should stop running around Ostia playing detective with her unconventional friends. She blames her father's change of attitude on his new ladylove, Cartilia Poplicola, and is determined to prove that the widow is a fortune-hunter, a witch, or even a murderess. Several signs, including a dream, make Flavia believe that following a trail guided by the twelve labours of Hercules will lead her to the truth. These are generally places in Ostia, such as the Hydra fountain and the Atlas tavern, but also events like the capture of the escaped lion or people such as the gladiator nicknamed the Cretan Bull. Flavia and the others pick up scraps of news and gossip about Cartilia and her family which they try to piece together. The detectives meet Cartilia's sister Diana and eventually discover her secret love for Aristo, which explains some strange events and clears Cartilia of wrongdoing. However, uncovering another secret destroys Marcus's trust in Cartilia, and Flavia is unexpectedly unhappy about it. A fever sweeps through Ostia and many fall sick, including Flavia and Marcus. The first wave of sickness, however, is just the precursor of a more deadly plague which will be important in the seventh book, The Enemies of Jupiter.