A prominent scientist during Victorian times, Sir Hugo (played by Robert Stephens), has a strong interest in early motion pictures. While filming his friends punting on the river, they meet with a fatal accident. Afterward, unusual occurrences appear in the photographs, suggesting that an enigmatic presence is inhabiting their deceased forms. Could this be linked to "The Asphyx" from Greek mythology? Joined by his son (Robert Powell), he embarks on an investigation hoping to capture one of these entities, perhaps even unlocking the secret to immortality. The production values are good, and the narrative along with its writing hold up well; the main actors, including Jane Lapotaire as Christina, provide some enjoyable moments. I felt it ran a little too long, but it’s still worth checking out.

Source on TMDB