Gemma, Duncan, and the boys are back in their Notting Hill house and enjoying a quiet spring in London when Gemma receives a plea for help from her friend and neighbor, Erika Rosenthal.
Erika has never shared much of her past, other than telling Gemma that she and her husband came to London before the war as refugees from the emerging Nazi regime in Germany. Her husband was a historian and was found murdered in a local park. His death was never solved. Now Erika tells Gemma that a necklace from her past has come up for auction - a necklace which was taken from her. Now Erika asks Gemma to find out where the necklace came from.
As Gemma works backwards, interviewing the staff at the auction house and looking into the records of David Rosenthal's death, her viewpoint is interwoven with Erika's vivid memories of her life as a young woman in London during and after the war. Then a young woman at the auction house is murdered and suddenly the case becomes very much centred in the present.