Part of Wikipedia's lengthy summary of the plot:
Somewhere, an evil entity tells Morgan le Fay that she has been prevented from breaking through to the earthly realm by a great wizard, and that she has three days to either defeat or kill the wizard and win over his successor to her master's side.Le Fay possesses a young woman named Clea Lake and uses her as a weapon against Thomas Lindmer, the "Sorcerer Supreme." She pushes him off a bridge to his death, but instead of dying, he slowly gets up and magically heals himself. His friend, Wong, looks after him and locates Lake for him. Suffering from psychic aftereffects of the possession and haunting dreams of le Fay, Lake is under the care of psychiatrist Dr. Stephen Strange at a psychiatric hospital. Strange has the potential to become Lindmer's successor by virtue of abilities and items inherited from his father, including a signet ring. Strange intuitively senses something very wrong, sharing Lake's nightmare about the previous day's events, but does not understand what is going on.
Here's the trailer:
Here's some more footage, including Morgan le Fay speaking with her demon master:
And here's the wizard battle:
Jessica Walter ruled in many different roles, but let's not forget her turn as the villain in the 1978 Dr. Strange. RIP. pic.twitter.com/pxxE6FAKr0
— Yeet Takeshi (@alex_navarro) March 25, 2021
The disc is available at Amazon.