The Wheel Spins by Ethel Lina White

The Wheel Spins ended up in my "must read" pile via Danielle at A Work in Progress. I downloaded it to my Kindle, and, true to form, I read the first part rather slowly, then finished with a mad dash. The book is extremely atmospheric. Iris Carr is trapped in a nightmare, and you are there with her. Alfred Hitchcock used this story as the basis of his film The Lady Vanishes, if that gives some insight into the mood of the story.
Iris has been vacationing in a quite remote location with a group of noisy friends. When it's time to go home, she lets them go on without her in order to enjoy a day or two of solitude and quiet. She gets lost during a walk and loses her sense of direction. When she can't find her way back to her hotel, and realizes that no one can help her because she doesn't speak their language, it gives her a fright. Then, already feeling unsettled, she loses consciousness on the train platform (sunstroke?) and nearly misses her train.

A rather annoying spinster-governess in her compartment latches onto her, and fills her ears with bits of gossip about the other passengers, stories of her home and family, and half-dropped hints about her highly-placed, secretive employer. Iris is bored by her, although she recognizes her fundamental kindness and goodwill, and after spending a few hours in company with her, she drops off to sleep for some peace. When she awakes, the lady is gone--not only from the compartment, but also, apparently, from the train, as well as from the memories and knowledge of every other passenger. No one will admit to seeing her with Iris.

Iris's recent unsettling experiences make her doubt herself. Did she imagine or dream the whole thing? But the growing conviction that Miss Froy (the spinster) both existed and is in trouble pushes Iris to put aside her selfishness and discover a way to rescue her, even at the risk of being suspected of madness.

Not a long story, but engrossing. It reminded me of that newer Jodie Foster movie, Flightplan (2005) , in which a mother dozes off on an airplane and awakens to find her child missing--a child no one will admit to seeing.

My Kindle copy of this book is lendable, and I will lend it to the first person who asks me. Just bear in mind that you'll have just two weeks in which to finish, so please ask only if you plan to read it for certain, as I can only lend it once.