A Fatal shooting. A vulnerable eyewitness. DI Ruth Hunter and her partner, DS Nick Evans, must track down the killers before they find a key witness - a ten-year-old boy, Daniel.

Ruth and nick are called to a fatal shooting at Chirk Castle, a well-known tourist spot in North Wales. The only witness to the murder is Daniel, the ten-year-old son of the victim. Ruth discovers that the victim was a small-time drug dealer and it seems that his killing might have been linked to stolen drugs. However, when a local girl is also brutally murdered, Ruth has to change the focus of the investigation as it is clear that the murderers will go to any lengths to cover their tracks.

With the case now faltering, Ruth begins to suspect that the key to solving the murders actually lies in Daniel's early childhood. Can she unlock the dark secrets of Daniel's past before the killers catch up with him?