Julius Caesar left his gardens to the citizens of Rome, a peaceful sanctuary across the Tiber. Now the gardens and their sacred grove are dangerous haunts, especially for women alone. 'Don't go to the Grove,' people mutter, but when her husband has to leave Rome, it falls to Albia to supervise his building project in an old grotto.

Why has someone buried tattered scrolls by obscure philosophers - and does it involve a worse crime than terrible writing?Soon that puzzle is overtaken. A woman disappears from her husband's birthday party; she meets a dire fate, then Albia learns that on the same night, two louche slaves given to her family by the brooding Emperor Domitian also vanished in the gardens. Apparently, it is well known that a killer lurks there.

The vigiles have failed to investigate properly for decades and this won't improve when the sinister agent Karus arrives. Albia must co-operate, in order to give the many victims justice and find answers for grieving relatives. But can she herself remain safe? And, after others have failed, can she at last identify the predator who has made the Grove his killing ground?