Intriguing premise but would want to read book one first

As someone who occasionally reads dystopian fiction, I found the premise of the book intriguing and the idea of a wall dividing north and south of a country to prevent 'infestation' conjured up thoughts of some current political parallels. I liked the use of different narrators. However, as others have commented, I think I'd want to have read the first book in the series first. Starting with the second book, I'd be worried there would be things I wouldn't understand about earlier events or too much recapping blogging down the story.