I walked into the house one evening and froze—our children’s nanny was stepping out of the shower, her hair dripping wet.

She quickly explained that our baby had spilled milk on her, and she needed to rinse off. But something about the scene unsettled me. My husband, who should have been at work, was still home.

Doubt gnawed at me all night. By morning, suspicion had taken root. I dug out an old security camera and discreetly set it up in the living room before leaving for the day.I walked into the house one evening and froze—our children’s nanny was stepping out of the shower, her hair dripping wet.

She quickly explained that our baby had spilled milk on her, and she needed to rinse off. But something about the scene unsettled me. My husband, who should have been at work, was still home.

Doubt gnawed at me all night. By morning, suspicion had taken root. I dug out an old security camera and discreetly set it up in the living room before leaving for the day.