I think this scenario is described in Deadline and/or Blackout so it didn't hold anything new to me plot-wise, but it's alarming to think the trilogy could've ended here. It's awful to think both Masons could be dead and the conspiracy buried. (Yes, I know it's all fictional and theoretical; you probably get what I mean.)

Though I am curious whether Grant had already decided to make Shaun immune to KA — because that adds another level of tragedy to it all. He would have gotten better. She would have lived.