Room is a novel by Emma Donoghue. The story is told from the perspective of a five-year-old boy, Jack, who is being held captive in a small room along with his mother. I think Donoghue but a lot of though and effort into creating Jack's "voice." And just as the cover says, the book is absolutely riveting.
Room won or was nominated for many literary awards and is being made into a movie which should be released in 2015 according to IMDB.