Did you find the first book captivating? then this would definitely drown you with its intensity. What started with the first book, completely takes on fire by the second book. The Rose Society is completely on a different level than the first book almost to the point that it feels a different world than the first book, Young Elites
If you have loved the Legend series by Marie Lu then there is no way that you should skip the elite series because the series just gets better with each succeeding books. Its rich in plot and characters making it worth the trouble and effort.