I have not read the original book, but a short prologue easily summed up the main events of Widows. However, while it might have got readers up to speed with the main events, I definitely feel like the book jumps right in where the last left off, so there isn't much in the way of explaining who the characters are and how they relate to the story. It sounds like an interesting story, but it definitely seems like readers will want to start with the first book.