"Prisoner in the Mirror" continues our season ending winning streak, offering Henry Daniell a third series role as Count Alexander Cagliostro, evil 18th century alchemist, escaping death by encasing his soul inside a mirror through which he can lure unsupecting victims to give up their mortal bodies for his own use, a vampire who desires life instead of blood. The opening scene features David Frankham's Marquis de Chantenay enticing a young woman to her death in the year 1910, a reign of terror conducted against his will by the wicked Count, forcing the innocent Marquis to foil his persecutor in covering the mirror glass entirely with black paint before taking his own life. Modern day professor Harry Langham (Lloyd Bochner) is composing a thesis about Cagliostro, examining the tomb of the Count's muse Yvette Dulaine (Pat Michon) to find her beauty still intact when by all rights she should have become a skeleton. When he finds the mirror in an antique shop it is shipped to his home for a place in his bedroom, eagerly stripping away the paint to search for signs of Yvette in the forbidding glass. His sweetheart (Marion Ross) finds herself neglected by his obsessions, culminating in Cagliostro taking control of Langham's body, but it won't be long before the police are on his trail after the strangling of a waterfront prostitute. Robert Arthur would go on to script "Dialogues with Death" and "An Attractive Family," but this would be his best crafted, most downbeat episode as directed by Herschel Daugherty, veteran of 16 THRILLER entries and two for STAR TREK. Daniell's appearance is disappointingly brief but excellent, while another familiar face is that of Frieda Inescort, from Bela Lugosi's "The Return of the Vampire," David Frankham soon to play opposite Vincent Price and Basil Rathbone in Roger Corman's "Tales of Terror." Boris Karloff himself did have one previous run in with Cagliostro, as he was to have been the subject of what evolved into Imhotep for Karl Freund's 1932 "The Mummy."