Pretty much exactly what it says on the tin - Angela Davis explains why prisons are an outdated concept perpetuating racism, sexism and class discrimination; She moves on to talk about the prison-industrial complex, which I thought was very interesting, and ends with a short paragraph on abolitionist alternatives to prison. That last part is what makes me give the book "only" 4 stars: I was sold on the idea of abolition when I started the book, I'm even more convinced now, but I would have liked a longer, more detailed reflection about where to go from now.