The love between a parent and their child knows no bounds.

While parenting styles have evolved over time, the caregiver's essential role as protector, provider, and teacher remains virtually unchanged throughout history.

Most parents spend countless restless nights worrying about the well-being of their children, and the thought of any harm coming to them is the stuff of nightmares.

But, for some, it's a very different and disturbing story.

Chilling accounts describe cases where caregivers have become the source of a child's suffering, committing acts of abuse so horrific they seem ripped from the script of a twisted horror film.