I have never read anything by Marie Lu and this looks really unique a different spin on the apocalyptic setting. The Federation has conquered almost every country except one Mara. An elite group of fighters called Strikers including the main character Talin to fight to protect it against them. The federation warriors seem really interesting they used to be human but now they are ghosts because they drank or where forced to drink a toxic substance. Could there be a horror angle to this? The one thing I hope is that we get a back story about how The Federation was about to take over.