Standalone sequel to "The Family Upstairs".

Early one morning on the shore of the Thames, DCI Samuel Owusu is called to the scene of a gruesome discovery. When Owusu sends the evidence for examination, he learns the bones are connected to a cold case that left three people dead on the kitchen floor in a Chelsea mansion thirty years ago.
Rachel Rimmer has also received a shock—news that her husband, Michael, has been found dead in the cellar of his house in France. All signs point to an intruder, and the French police need her to come urgently to answer questions about Michael and his past that she very much doesn’t want to answer.
After fleeing London thirty years ago in the wake of a horrific tragedy, Lucy Lamb is finally coming home. While she settles in with her children and is just about to purchase their first-ever house, her brother takes off to find the boy from their shared past whose memory haunts their present.
As they all race to discover answers to these convoluted mysteries, they will come to find that they’re connected in ways they could have never imagined.