A cruise ship officer from Hong Kong disappears during a port stop in Holyhead on the North Wales coast and a missing person investigation turns up no leads. On the same cruise, an international police operation to break an art smuggling ring loses track of three valuable Russian paintings thought to be on board. Four months later the younger sister of the missing sailor becomes a student at Bangor University, nearby. The Metropolitan Police Art Crime Unit wants to know why she is in the UK and whether it has any bearing on their case.

Constable Catrin Sayer is looking for promotion and a new role away from drug squad work in Brixton. Coincidence and her Welsh background lead her to go undercover and assist the investigation. She is twenty-four at the time; keen, ambitious, trying to balance her work as a police officer with her interests as an artist, a ceramic decorator.