Defense Grid 2: Aftermath is the first official expansion to Defense Grid 2 - 10+ years after launch.  Five advanced levels allow for great flexibility and creativity in tower placement and feature a new storyline with your favorite AI Fletcher. Protect the Cores on these advanced levels.  Once installed, go to DG2's Campaign from the main Menu and continue onward to the added new chapter - found just to the right past Chapter 5.  A new adventure for the Commander and Fletcher begins!