Harry Bosch is working as a part-time detective in San Fernando, outside of Los Angeles, when he gets an invitation to meet with ageing aviation billionaire Whitney Vance. At eighteen, Vance had a relationship with a girl called Vibiana Duarte, but soon after becoming pregnant she disappeared. Now, as he reaches the end of his life, Vance wants to know what happened to Vibiana and whether there is an heir to his vast fortune. Bosch is the only person he trusts to undertake the assignment.