There's this lady, see, and then she vanishes. Here's what the title doesn't tell you, though. When she disappears, she's on a train. They should have called it The Lady Vanishes on a Train. That would answer all questions.
We start with the train socked in by an avalanche. Travellers are forced to stay the night in a humble inn overrun with guests. We meet a young American woman travelling to see her fiancee, an overbearing musicologist (Michael Redgrave) who is studying local music, a pair of cricket fans trying to get back to London to see an important match, a "married couple" trying to stay anonymous, and the old Miss Froy (Dame May Whitty).
A potted plant, meant for our Miss Froy, hits young Iris (Margaret Lockwood) instead, but isn't hurt too badly. She boards the train and meets up with Miss Froy and has a cup of tea. She falls asleep and when she wakes, Miss Froy is nowhere to be found and other travellers deny ever seeing her. The musicologist who annoyed her back at the inn now decides he believes her. Perhaps he saw her in better light. Anyhow, a brain surgeon who happens to be on the train finds the case to be fascinating and decides to help explain the disappearance. The blow to the head made her think she saw the lady from the inn on the train. See? That explains everything. Pretty Iris and annoying musicologist don't seem to think so. They go on a hunt for the answer. That's where the story description ends. Have fun seeing how it all pans out.
Michael Redgrave is the dad of Vanessa and Lynn, showing where they get their tall gene. The two cricket fans (who could love such a horrible, horrible sport?) were so popular they appeared as background characters in two other movies. They were kinda amusing, as was the story. The end was more than a bit ridiculous, but as a whole this was a very pleasing movie. Perhaps more so if you pretend you don't know if Miss Froy was imagined or not. AMRU 3.5.
"I've no regrets. I've been everywhere and done everything. I've eaten caviar at Cannes, sausage rolls at the dogs. I've played baccarat at Biarritz and darts with the rural dean. What is there left for me but marriage?"