Free Ebook: Wool, Part One by Hugh Howey

As of now, Wool (Part One) by Hugh Howey is free to download on Amazon (US, ES). It's not the first time that this ebook is free, but I think I haven't posted about it before. This is the synopsis:

Thousands of them have lived underground. They've lived there so long, there are only legends about people living anywhere else. Such a life requires rules. Strict rules. There are things that must not be discussed. Like going outside. Never mention you might like going outside. 

Or you'll get what you wish for.