The Unmarked Door is opening.
Not the way doors open. Not hinges creaking or locks clicking or handles turning under a hand that isn't there. It's opening the way a wound opens—the edges pulling back from something that was sealed shut, something the Threshold itself had agreed to keep closed, and now the agreement is dissolving into sodium-orange light that doesn't belong to either world.
I'm standing thirty metres away, and I can feel it. Not see it. Feel it. The way you feel a question you haven't answered yet, sitting in your chest like a stone.
Three centuries. The Unmarked Door has been sealed for three centuries. I know this the way I know my own name—it's written into the stone of the Threshold, written into the crystal that grows in the gaps between mortal brick and fae marble, written into the air itself which tastes like copper and old decisions. The Threshold remembers what it has locked away.
I move closer. My feet know the way—wet concrete bleeding into smooth fae stone, the transition so gradual you can't pinpoint where one world stops and the other begins. That's the Threshold's trick. That's what makes it a doorway instead of a wall.
The door itself is crystalline, but not like fae crystal. It's the colour of something forgotten—not quite grey, not quite silver, shot through with veins of what might be rust or might be dried blood. The frame around it is mortal stone, but warped. Angles that don't quite square. Corners that suggest other dimensions if you stare too long.
I pull fae-sight down like a veil and look deeper.
Nothing. The door reads as sealed. Locked. Absolute. But I can see the edges moving. Breathing. Opening.
I shift into mortal logic instead—the careful, procedural thinking that made me useful to both sides in the first place. A door opens because something is forcing it. Pressure from the other side. A mechanism failing. A choice someone made, actions taken, consequences arriving.
The stone around the frame is unmarked. Undamaged. There's no pressure, no force, nothing that should be moving.
My hands are shaking.
I pull out the communication-stone—it's warm in my palm, fae-crafted but keyed to mortal frequencies, a thing that shouldn't work but does because I built it to bridge the gap. I reach out to the High Counsel first. They answer before the second pulse of light.
*Aerin.* Not a greeting. A demand.
"The Unmarked Door is opening. I need clearance to investigate. I need time to understand—"
*How long?*
"I don't know. The mechanism is—it's not following precedent. It's not following any logic I can parse. I need to examine it more carefully, speak with the mortal archives, cross-reference the fae records, understand what was sealed and why, understand what could cause—"
*You have one hour.* The High Counsel's voice is thin as wire. *If the door opens fully, if anything crosses through, you are responsible. You are the ambassador. You stand at the Threshold. You decide.*
The stone goes cold.
I flip the frequency. The mortal authorities pick up on the third ring—they're always slower, always more cautious, always treating the Threshold like it's a problem to be managed instead of a living thing to be understood.
"There's a breach. Potential breach. At the Unmarked Door."
"What's a breach?"
"A sealed doorway is opening. I don't know why. I don't know what's on the other side. I need time to—"
"How much time?"
"I don't know. It depends on whether the opening is accelerating, whether it's a slow degradation or a sudden collapse, whether the fae side is aware, whether they're involved—"
"Aerin. How. Much. Time."
The stone is slick in my hand. "One hour," I hear myself say. "Maybe less."
"Then you have thirty minutes to tell us whether we need to evacuate the mortal districts adjacent to the Threshold. Thirty minutes to tell us if this is a fae incursion or a natural catastrophe or something else entirely. Thirty minutes to decide, Aerin, because we can't afford to sit at a table and think about it. People's lives—"
I cut the frequency.
I'm standing at the Threshold's central crossing now. The place where the geometry is most unstable, where the angles hurt to look at directly. I can see both doors from here—the one that leads deeper into the fae realm, the one that leads back into the mortal city. Both are sealed. Both are exactly where they should be.
The Unmarked Door is opening wider.
And I understand, all at once, with the clarity of a thing I've always known but never let myself see—
The door isn't opening because of anything from the other side.
It's opening because I've been standing here. Suspended. Caught between the two frequencies in my hand, between the two demands, between the two worlds that will never stop pulling at me, that will never let me rest. The Threshold doesn't tolerate paradox. It demands choice. It demands you move through or you move back, but you cannot stand still indefinitely. And I've been standing still for so long that the Threshold itself is rejecting me as a contradiction—a thing that belongs to both worlds and therefore belongs to neither.
My indecision is a wound. The door is opening because I'm the wound.
The High Counsel wanted me to seal it. The mortal authorities wanted me to protect against it. Neither of them understood that the only way to close the door is to move through it. To choose a side. To accept that being an ambassador means eventually you have to stop standing at the crossing and actually belong somewhere.
I've been so careful. So deliberate. So desperate to weigh every consequence before acting. But the consequence of that choice is this—paralysis made manifest, a door opening because I refuse to walk through any other one.
The Unmarked Door is almost fully open now. Light spills through it, but it's not fae light and it's not mortal light. It's the colour of the choice I've been avoiding.
I step forward.
I don't try to see which side it leads to. I don't consult the stones in my hands. I don't think about the High Counsel or the mortal authorities or what it means to abandon my role as ambassador. I just walk through the opening, and as I cross the threshold, I feel the stone beneath my feet shift—feel myself moving from suspended to committed, from both to one, from the careful deliberation that kept me safe to the sharp, irreversible clarity of a choice that can't be unmade.
The door closes behind me.
And for the first time in longer than I can measure, I'm not waiting anymore. I'm already here.