The young female protagonist in Scanners III is named Helena Monet (played by Liliana Komorowska). She is the daughter of a scientist who developed a new type of synthetic scanner drug that enhances the psychic abilities of scanners. The drug is highly addictive and dangerous, causing instability and paranoia.
Helena, who is a scanner herself, initially uses the drug to help her focus and control her powers. However, as she becomes more addicted, she starts to lose her grip on reality, becoming aggressive and power-hungry. She begins to use her abilities to control and manipulate those around her, including her family members and other scanners.
Meanwhile, Helena's brother Alex (played by Steve Parrish), who is also a scanner, becomes aware of his sister's descent into madness and decides to take action. He must confront her in a final showdown to prevent her from causing any further harm.
The film is directed by Christian Duguay, who previously directed Scanners II: The New Order. It features the trademark special effects of the Scanners series, including the iconic exploding head scene. The film explores themes of addiction, power, and family loyalty, and is a thrilling addition to the Scanners franchise.