The main story originally seen in Dark Birth has changes a bit. Every chapter has changes as it benefited from some great content editing and line editing and so on.
Some things have been removed, while other things have been added. One of the chapters from Dark Threats, (the one where the witches get kicked out the the barrier), has been rewritten and put back in.
The chapter where the Dunston children meet Eliza has been completely removed and something else is in it's place.
What took it's place? What has been added in more than one spot in the narrative? More Salem Witch Trials! Yes, that event now has a stronger part of Annabelle and Roland's first adventures.
In fact, a certain real life historical figure: Tituba, the woman whom the Afflicted Children first blamed for their condition, has gained a nice little part in not only this novel, but the overall series!
So if you like Annabelle's story, if you want more of her, I suggest checking out the book because no matter where you factor into reading the prior versions, THIS version is new, and the OFFICIAL telling of her story.
I suggest getting in on the ground floor of this series. Things are going to get crazy!
Vampires at the Salem Witch Trials!