The story is a found manuscript, or rather, related tale, of a group of people who go missing during a military conflict in India and find themselves in a mysterious Tibetan monastary. I don't want to say much more about it, because I think it's a text whose pleasures unfold gradually, but one of the things I found intriguing was the guiding principle of the monastary - moderation. There are plenty of different notions about how to organize a utopia, but this is a particularly interesting one. They're moderately virtuous, moderately chaste, moderately disciplined... it's a curious approach.
Also, for a book written in 1934, it's kind of amazing how enlightened it's thinking on race is. It tackles a lot of orientalist stereotypes in a really intelligent way, I was impressed. In this day and age, where Tibetan Buddhism is the hippest thing on the block, ie, the orientalist impulse has gone whole hog in the other direction (which is less disastrous perhaps, but still has some serious flaws), it's nice to find a more balanced approach.
Really, a very interesting book. Quite recommended.