I am trying to remember the name of a series with quite a few (shortish) books, although I am having trouble remembering the details of the series, as well as the name of the books.
I remember that they start off inside this walled village or location, where a young character discovers that life outside the place they live is not how it seems (I think the outside is projected from their windows and in reality, everyone outside is poor and starving).
The protagonist then goes on adventures trying to stop something or save someone (not sure?) over the next books - including some involving quicksand and rescuing someone from captivity who spoke in a secret/coded language.
They are reasonably popular as I remember seeing them at a lot of bookstores. Thanks for your help and hopefully at least one of you knows the series of which I am thinking about as it has been bugging me for a week or so.