At nearly one hundred years old, Thalia Mars is a far cry from the patients child psychologist Dr. Alex Delaware normally treats. But the charming, witty woman convinces Alex to meet with her in a suite at The Aventura - a luxury hotel with a checkered history.

What Thalia wants from Alex are answers to unsettling questions - about guilt, patterns of criminal behaviour, victim selection. When Alex asks the reason for her morbid fascination, Thalia promises to tell all during their next session. But when he returns the following morning, his question goes unanswered, and new ones arise...

In their most puzzling investigation to date, Alex and homicide detective Milo Sturgis must peel back the layers of a fascinating but elusive woman's life.

For Thalia Mars is a victim like no other, an enigma who harboured nearly a century of secrets and whose life and death draw those around her into a vortex of violence.