A pillar of the local community is found dead at the charity he runs, and Antonella's friend is arrested for his murder. Trying to clear the woman's name, Sylvia follows a trail of blackmail, family secrets, and illicit love.

Freelancing for MI6, Sylvia poses as the PA for a diplomat's widow at her luxurious lakeside villa. She's keeping watch on a South American politician, but when a dead body is found in the lake, Riva is astonished to discover Sylvia already onsite.

When an old foe abducts Sylvia, she must draw on her formidable reserves of physical and mental resilience to escape. While Riva investigates through official channels, Henry and Isabel run their own covert operation, all of them racing to save her.