Grumio meets Justin, the father who left him on a hill as a baby and who now wants to make up for lost time, and Marcus and Delphine come to terms with their respective pasts.

When Marcus's parents visit for the weekend, he is keen to keep them and Delphine as far apart as possible. Meanwhile, Stylax pursues a romance with Ursula, one of the Vestal Virgins who guard the city's sacred flame, and Grumio spots a business opportunity.

As a crime wave sweeps the city, the boys join a Roman military fitness class to protect themselves on the streets. Flavia introduces some dubious new security measures at work. Grumio starts dating Agatha, a talented baker who may well be a feeder.

The boys meet their new neighbour, a weatherman. Marcus uses the forecast of a small tremor to bring excitement to his relationship with Delphine. Stylax tries his luck with an attractive new colleague, while Grumio discovers Indian food.