Written from the point of view of Jack - a surprisingly literate 5-year-old, the book is set in a room. The room is lined with cork tiles, has a skylight window secured with industrial mesh and is separated from the world by steel door with an electronic lock. The room is the world for Jack, who was born in it and has not left it since. The room is a prison for his mother, who was kidnapped at 19 and spent the last 7 years there. She protects her son by building an illusion that becomes his reality. She teaches him that the room is the world and there's nothing real outside it. The pictures he sees on TV are just that - and only in TV. They don't really exist.The life on the inside is wondrous for the boy - rich, entertaining and full of the most important thing in the whole world - his Ma. He has her at his side all the time - they even take baths together. Also, whenever he wants to, he can "have some" - since his Ma never saw the reason to stop breastfeeding him. Jack's life is perfect, with occasional interruptions when he worries about his Ma. That is because almost every night she gets a visit from "Old Nick", the man who is their keeper and provides both the most basic supplies and the solid barrier between the room and the world.
This book is heartbreaking. It puts in question all the conventions of the modern society - especially methods of rearing children. Jack's Ma is surely better off on the outside, but what about Jack?
Room may just be a giant metaphor for everything from the world to a single cell. Limited and locked it's quite perfect, really. And that's the scariest and the most heartbreaking thing in the world.