Is a mystery that has bewildered police for 50 years about to be solved? On 7 November 1974, the dead body of a children’s nanny, Sandra Rivett, was found. The chief suspect was the seventh earl of Lucan, who had disappeared. Thirty years after the murder, Neil Berriman discovered he is Sandra Rivett's biological son. Neil revisits key moments in the crime, starting on the night of the murder.

In this hunt to find his mother’s killer, Neil tracks down Lord Lucan’s brother. He claims that the missing aristocrat did escape England and create a new, spiritual life for himself in the Far East. Then a letter lands on Neil’s doormat reporting the sighting of the fugitive as a monk in Australia. Neil heads down under and immerses himself in a network of Buddhist devotees.

Investigating his mother’s murder and searching for the prime suspect, Neil makes a breakthrough in the case. Having acquired Lucan’s medical notes, he starts his own facial analyses. He finds a tiny nick in the nostril that he feels may be a crucial key to identifying Lucan. Computer analysis of the images of the Buddhist monk he suspected, and Lord Lucan, produces an extraordinary result.