Astaroth did not travel to Yeun.
He had no interest in kneeling in muddy fields or testing children with clever questions, the way Beelzebub and Satan, in their very different ways, apparently had.
His method had always been slower, quieter, and in his own estimation, far more reliable than standing in front of something and simply feeling that it was true.
Feelings lied.
Records, if read carefully enough, rarely did.
So while Beelzebub returned to his duties governing Gluttony and Satan retreated into whatever brooding silence he preferred after being unsettled, Astaroth descended into the deepest levels of his own tower, into archives even most of his personal scholars weren’t permitted to enter, and began to search.
He was looking for something specific, something the tablet’s fragment of prophecy had not explained and Beelzebub’s account, however detailed, could never have answered.
Not who the child was.
Not what he would become.
Astaroth wanted to know where the soul inside that small farmer’s body had actually come from, because in four thousand years of study, he had never once encountered a soul his methods couldn’t at least partially trace.
The first two years of searching turned up nothing but confirmation of what he already suspected.
Every soul in the known world, mortal or demon, human or otherwise, carried a signature, faint but detectable to those trained to look for it, tracing back to its point of origin.
Souls born in Elysara carried the resonance of Elysara itself, a kind of quiet birthmark written into their deepest layer, regardless of what body they wore or what life they lived.
Astaroth had catalogued thousands of these signatures over the centuries, cross-referenced them against bloodlines, kingdoms, even specific rivers and mountain ranges known to leave particular traces on the souls born near them.
He requested, through careful, indirect channels that never mentioned Lucifer’s name directly, a soul reading be taken of the boy.
Beelzebub, when asked, refused outright, unwilling to subject a child to a process that, however harmless in theory, had never actually been performed on someone whose nature remained entirely unknown.
Astaroth hadn’t pushed the matter, not yet, choosing instead to work around the refusal rather than against it.
Fenwick, still stationed near Yeun under a different guise, had collected small things instead.
A strand of hair, given freely by Maera when the disguised merchant complimented the boy’s dark curls during a routine visit.
A wooden carving, one of Lucifer’s own small projects, traded for a length of good rope.
Nothing invasive.
Nothing that would have alarmed anyone paying attention.
But enough, when finally delivered into Astaroth’s careful hands, for a partial reading, faint and imperfect, but a reading nonetheless.
What it showed unsettled him more than anything he had encountered in centuries of study.
Nothing.
Not absence in the sense of weakness, the way a stone or a piece of dead wood might return nothing because it had never held a soul at all.
This was different.
It was the particular nothing of something actively resisting being read, or something so far outside the categories his methods were built to detect that his instruments simply had no language for it, the way a scale built to weigh stones has no way of measuring the wind.
Astaroth spent the following months tracing something else instead: not the soul itself, but the shape of the silence around it.
He returned, for the first time in nearly a century, to the oldest section of his archive, a chamber sealed behind three separate locks that required his blood, his name spoken aloud, and a phrase in a language so old even he had to consult his own notes to pronounce it correctly.
Inside were records predating the Seven Demon Kings entirely, fragments salvaged from the era before the current order of Hell had been established, when the boundaries between the Abyss and the world above had been far less settled than they were now.
Among those fragments, buried beneath centuries of dust and long-forgotten cataloguing systems, he found references to something he had encountered only in passing before, always treated as myth rather than history: accounts of souls that did not originate from any world the ancient scholars recognized.
The records called them, in a phrase that lost something crucial in translation no matter how carefully Astaroth worked it, wanderers between doors, souls that belonged to no single reality, capable of crossing between them under circumstances the old texts described only in riddles and warnings, never in clear explanation.
One fragment, badly damaged, contained a single surviving line that made Astaroth sit motionless at his desk for the better part of an hour after he finished translating it.
Where the door does not exist, the wanderer’s soul becomes the key.
He read it seven times before setting the fragment down.
He did not share this immediately with the other six.
Not out of malice, and not entirely out of the caution that had defined his reputation for centuries, though both played their part.
He simply did not yet understand enough of what he’d found to present it as anything other than speculation, and speculation, delivered too early to minds already divided over Lucifer, real or false, could do more damage than silence.
Instead, he wrote to Beelzebub, carefully, choosing words that revealed just enough to justify the request without revealing everything driving it.
I have reason to believe the boy’s nature is more unusual than even you suspect.
I am not yet certain what that means, only that it should be understood before the world learns of him, not after.
When he is old enough, I would like to speak with him myself.
Not to test him, as Satan did.
To listen.
Beelzebub’s reply came weeks later, brief, and characteristically direct.
When he is ready.
Not before.
Astaroth folded the letter and set it beside the damaged fragment on his desk, the two pieces of parchment sitting side by side like two ends of a question neither could fully answer alone.
He looked out from his tower’s highest window, toward the deep red horizon that never fully darkened, toward a sky that had, months ago now, flickered once in a way no one else in Hell had thought worth mentioning.
Wanderer between doors, he thought again, turning the phrase over slowly, feeling its weight settle into something he couldn’t yet name but suspected, with the particular unease of a scholar who had learned to trust his instincts more than his evidence, he would eventually come to understand far better than he wanted to.
And where the door does not exist, he continued silently, watching the horizon as if it might answer him directly, the wanderer’s soul becomes the key.
A key opened things.
That was, after all, its entire purpose.
The question that kept him awake long after he should have retired for the night was not whether Lucifer was the key the ancient fragment described.
It was what, exactly, that key had been made to open, and whether anyone, prophecy or Demon King or the boy himself, actually understood what waited on the other side of that door once it finally swung open.