Lucan follows one man's hunt for the truth about the murder of Sandra Rivett.

On November 7, 1974, the dead body of a children's nanny, Sandra Rivett, was discovered in a mail sack in the basement of a Belgravia townhouse. The chief suspect was the father of the children, an Eton educated gambler called Richard John Bingham, the seventh earl of Lucan, who had disappeared. While most of Lord Lucan's friends and family insisted that he had taken his own life, no body has ever been found. The manhunt for Lucan has lasted decades.

This series follows the deeply personal quest of Hampshire builder, Neil Berriman, whose conviction in his own ability to solve the mystery is unshakeable. The case has consumed Neil for the last two decades, and it has done so for very personal reasons: Neil's birth mother was Sandra Rivett.