The New World by Patrick Ness is a short story prequel to his astoundingly great Chaos Walking series. The series consists of 3 novels and 3 short stories. They are considered YA Sci-Fi / Dystopian Adventure stories.
You can get a copy of the Kindle edition of The New World for free on Amazon and you can get free digital copies of all three short stories at the Chaos Walking website. Spoiler alert: don't read the other two short stories until you have the 3 novels that go with them!
I loved this series! The characters are great, the setting is believable, and the stories are wonderful! They are definitely keepers.