The following contains spoilers for Death of the Inhumans #4 written by Donny Cates, drawn by Ariel Olivetti, colored by Jordie Bellaire, and lettered by Clayton Cowles.
When you title your book Death of the Inhumans, it's hard for anyone to really see this story as anything other than, well, the death of all the Inhumans in the Marvel Universe. This title, combined with the failure of the Inhumans brand in both comics and television, led many to believe the publisher was simply getting rid of assets that don't sell.
Of course, Marvel knew you were all thinking that, so Donny Cates and Ariel Olivetti leaned way in for the first four issues of the series. Then, just when it looked like the franchise was circling the drain, something unexpected happens in issue #4 that changes everything.
To recap, in the first issue, the Kree launched a devastating attack on Attilan that killed most of the Inhumans in existence, leaving only the Royal Family as survivors. The genetically engineered super-Inhuman known as Vox was then unleashed, and he managed to slay Triton, Maximus, Lockjaw and, in Issue #4, Crystal. It felt like this would be the ongoing pattern for the rest of the comic as Cates and Olivetti systematically destroyed the remaining Inhumans, but the end of the issue revealed the truth about everything.
Thanks to the interference of Beta Ray Bill, the Royals were finally able to overpower Vox, only to realize that the villain they had just killed was actually Maximus in disguise. It turns out Vox isn't a person -- he's programming, and the voice power everyone assumed was vaporizing his targets was actually just teleporting them instead. Surprise, everyone's still alive (except for Maximus, who now appears to actually be dead).
After Crystal's apparent death, we see she has been transported to places unknown, where Kree scientists are seen experimenting on their captives. While Lockjaw isn't seen, Triton appears to be in some kind of tank, along with other beings who are undoubtably Inhumans. Crystal is now doomed to be the next Vox.
This revelation changes everything we thought we knew about Death of the Inhumans, and turns the purpose of this story into something else entirely. No longer is this the swan song for the Inhumans, or the editorial mandate to put a suffering property out of its misery. Instead, it has become something of a tablesetter.
Depending on how the series ends, Death of the Inhumans could give the Royal Family a new beginning and set the stage for a new adventure. Since Marvel wanted us to believe they were all going to die, we really don't know where these characters will appear next. Sure, they could all still end up dead in the end, but chances are this is all leading to something bigger and (hopefully) better than the torture Death of the Inhumans has put Black Bolt and his people through.