Margaret Lockwood is quite compelling as "Lydia" in this tense mystery of a woman who encounters a French gent "Paul" (Paul Dupuis), romance ensues and they fall in love. Throughout their courtship, though, she suffers from increasingly worrying dizzy spells that a doctor confirms will lead to blindness. Horrified, she flees from her beau and takes up in an abbey where she considers holy orders. Luckily, the abbess insists she rejoin the world and she rekindles her romance with the Frenchman, they marry and retreat to his father's chateau. Initially welcome, she soon senses that someone is out to get her, and as the plot slowly develops we are drawn into quite a sinister web that has no shortage of potential perpetrators. Chief amongst them is their neighbour "Verity" (the excellent Kathleen Byron) who has designs on the husband. Finding her life unbearable, she, and her maid "Rosa" (Thora Hird) return to her old life were she encounters another surgeon who thinks he can fix her sight... It's at this point that the story takes a bit of downturn. Up til now, the tension had increased consistently with Byron and Lockwood squaring up nicely, but the ending is just too fanciful (although it does contain the best scene in the film). The men folks contribute little, too - Maxwell Reed is pretty hopeless and Dupuis pretty flat as her husband. Still, it sustains the mystery well enough for the most part and Lockwood is on good form.