When Detective Erika Foster receives a tip-off that key evidence for a major narcotics case was stashed in a disused quarry on the outskirts of London, she orders for it to be searched. From the thick sludge the drugs are recovered, but so is the skeleton of a young child.
The remains are quickly identified as seven-year-old Jessica Collins. The missing girl who made headline news twenty-six years ago.
As Erika tries to piece together new evidence with the old, she must dig deeper and find out more about the fractured Collins family and the original detective, Amanda Baker. A woman plagued by her failure to find Jessica. Erika soon realises this is going to be one of the most complex and demanding cases she has ever taken on.