Ruth Galloway, forensic archaeologist, spends her life looking at death. But now death has found her, with the news that her long-time friend Dan Golding has been killed. Ruth's grief soon turns to suspicion when she receives a desperate letter from Dan, sent the day before he died. He had made a ground-breaking discovery - and was petrified of the consequences. Ruth is compelled to travel north to investigate further, alongside DCI Harry Nelson who is also drawn into the case. But where Ruth goes, so does her daughter, Kate. This time, the risks are even higher.