A planned school trip to the amazing open air National History Museum of Wales ends early with the disappearance of a child. Is he just playing hide and seek or is it the work of a criminal with designs on the lottery millions of the little boy's mother? DCI Martin Phelps and his team are back together just in time to take on the case but what started off as a possible kidnapping ends with the discovery of two bodies, with one being nothing but bones and totally unrelated to the original crime. The investigation exposes the complexities of family relationships but these are gradually untangled as a criminal is brought to justice and a long standing mystery solved. All of this whilst Martin and his team are anxiously awaiting the results of a major organisational review that may in the future radically change the team.