With WWII raging across Europe, local boys discover a woman's skeletal remains stuffed inside of a hollow wych elm. They pledge not to say anything but one cracks under the pressure and confesses to his parents. Police aren't sure if it's satanic or espionage-related and no one knows who she is. 3 years later, a graffiti artist dubs the woman "Bella" and now she's known worldwide but yet, she remains unidentified. 

Was she a witch? A sacrifice? A Nazi spy?