Roman Britain: Late Autumn AD 370 
Summoning Canio to his Villa Censorini (Chedworth, Gloucestershire), Caristanius Sabinus, governor of Britannia Prima, informs him that he has been ordered to find a certain ancient figurine of the Underworld goddess Hecate, which he has reason to believe is in Canio’s possession. 
Canio denies that he has it, or that he ever had it – which is half-true. But Sabinus doesn’t believe him, and Canio is vulnerable to blackmail. 
And so, accompanied by a strange woman called Bodicca and a motherless boy calling himself Maximus, he journeys through a land slowly descending into winter, seeking a replica figurine good enough to deceive Sabinus. 
 It may not end well.