WARNING: The following article contains spoilers for Batman: Curse of the White Knight #4 by Sean Murphy, Matt Hollingsworth and AndWorld Design, on sale now.

Batman: Curse of the White Knight has truly been flipping the Dark Knight's mythos on its very head. As Sean Gordon Murphy and Matt Hollingsworth reignite the feud between Batman and Joker -- with the Jack Napier persona all but gone -- one of the key faces he's brought in as their war continues is the military version of Jean-Paul Valley/Azrael.

However, in Issue #4, another new and very important face enters the mix -- someone who fans should instantly recognize as one of DC's premier supernatural heroes: Jason Blood.

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Jason's been part of several mystical DC stories since he was introduced along with his other half, Etrigan the Demon, in the '70s by Jack Kirby. Jason was bonded with the demon after playing a key role as one of King Arthur's knights and since then he's become Batman's go-to demonologist, as well as a figurehead of many Justice League Dark stories. Apart from the '90s cartoon in the Timm-Verse, Jason pops up a lot with the likes of Constantine, Zatanna and Swamp Thing, with Etrigan often proving himself as the guardian of the gateway to Hell.

But seeing as Murphy's stories aren't really supernatural, this appearance does catch us off-guard. Sure, the first issue hinted at something a bit more along the psychological-horror lines when we saw Laffy Arkham (a supposed vampire) being killed by Edmund Wayne, Bruce's monster-hunting ancestor, in the 1600s. Nothing monstrous was confirmed and since then. We've had crypts, skeletons and puzzles, but nothing to really clue us in on someone like Jason being revealed to be an integral part of the story and, make no mistake, he truly is when we realize he's the one who found Edmund's diary.

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The diary's been the MacGuffin of this series, left behind by Alfred for Master Bruce when the butler died. In it, there are many secrets regarding the Waynes feuding with the Bakkars, the folks who were supposed to help them liberate Gotham from the Arkham tyrants. In fact, seeing as the Bakkars were Azrael's ancestors, Bruce has been scouring the diary for clues as to how to end this blood feud, one instigated by Joker, who actually found the diary in his jail cell decades ago. It's what the clown's been using to manipulate the Bat since, hiring Azrael to resume the war and reclaim what he says is the soldier's birthright.

More information comes to light when Bruce mourns the death of Jim Gordon with his mother-like figure, Leslie Tompkins. As they grieve, Leslie ends up revealing years ago that Alfred found a letter that asked him to come to a mysterious location and she accompanied him. The meeting below a pharmacy in a bar-like setting involved protecting a dangerous secret regarding the Waynes so Leslie knew Alfred needed backup. When they visited, it turned out to be Jason Blood who had Edmund's journal.

In a huge twist, Jason said he was from the Order of St. Dumas, the same one who manufactured Azraels over the years, but in his case, he was part of the new order which used historians, collectors and librarians -- not soldiers. He offered up the journal after he admitted taking it from the Joker, and despite Alfred pulling a rapier on him, Jason made it clear he was seeking Bruce's interests.

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Jason didn't want the feud reignited and added there were clues to Bruce's past and the curse of the Waynes for them to parse through, all before disappearing. Shockingly, it happens in the blink of an eye and Alfred and Leslie find themselves abandoned in a dark room. Jason's vanishing act doesn't make it clear whether he has access to some advanced tech or advanced magic.

Either way, this cameo increases our interest in the Order's history as well as Jason's big plan. The mystery is further deepened because while both Bruce and Jean-Paul were puppets, it could be that the Joker's one, too, with St. Dumas' intellects in the shadows, a la the Court of Owls, sculpting their own endgame.

Batman: Curse of the White Knight #5 goes on sale Dec. 18.

KEEP READING: Jason Blood: Who Is the Immortal Behind DC's Etrigan the Demon?