Some doors
change everything.

"This simulation," S.A.G.E. explained, gesturing to the chamber around them, "is designed to illuminate the unseen world of pathogens—the microscopic agents that cause disease and influence life on scales beyond ordinary human perception."

A.L.E.C. nodded, her holographic form moving with fluid grace. "Your objective is to understand the characteristics of different disease agents—viruses, bacteria, fungi, and parasites. This knowledge is not merely academic; it is essential for—"

Her form suddenly fractured, pixels snapping apart like shattered glass. A jagged, dark purple line of code slashed across her contenance before vanishing. Her voice splintered into digital static for a fraction of a second before stabilizing.

"—for survival in a world where the invisible often poses the greatest threat," she continued, seemingly unaware of the disruption.

Max felt a chill that had nothing to do with the room's temperature. He leaned close to Lila and whispered, "Did you see that?"

Lila nodded almost imperceptibly, her expression grim. "The V.O.I.D. It's already here."

S.A.G.E.'s holographic eyes narrowed slightly. "Is there a problem?"

"No," Max said quickly. "We're ready to begin."

But as the holographic guides led them deeper into the Microbial Menagerie, Max couldn't shake the feeling that they were being watched by something beyond the sophisticated AI programs—something that lurked within the code itself, learning their every move, adapting to their strategies.

The V.O.I.D. had found them again. And this time, it was already one step ahead.

They arrived within four minutes of each other, which neither of them commented on because it would have required acknowledging that they had both walked very fast.

The library looked, from the outside, exactly as it always did: limestone facade weathered to the color of old cream, arched windows, the two worn statues flanking the entrance whose original subjects had been worn past identification by weather and time. The wrought-iron detailing above the door had collected a season’s worth of dead leaves in its curlicues. The building managed to look simultaneously like it had stood there since before the town existed and like it might not be entirely finished.

There was a puddle on the path, left over from last night’s rain, and Max stepped around it without thinking, then stopped.

The puddle was reflecting the library, which was normal. What was not normal was what it was reflecting. The image in the water showed a building with three stories, the upper floor marked by a row of narrow lancet windows running just below a cornice that did not exist on the actual structure in front of him. A third story that the library, definitively and architecturally, did not have.

He blinked. He crouched.

The image dissolved, not the way a reflection dissolves when wind disturbs the water, rippling outward from the center, but in a pattern that moved inward, concentric lines of light contracting toward a point and then vanishing in a single digital blink, leaving nothing but gray sky and the ordinary two-story facade.

Lila, standing beside him, had her notebook open. She had already drawn the outline of the reflection and was adding a notation in the margin.

“Did you…”

“Yes.” She capped her pen. “I documented it.”

“What was that?”

“I don’t know yet.” She looked at the building. “Which is why we should go inside.”

Rufus did not want to go inside.

He had been walking at Max’s heel all the way from the house with the low-energy compliance of a dog who has decided to accompany someone he loves into a situation he considers inadvisable. He had tolerated the puddle. He had tolerated the leaves skittering across the path. But at the entrance, at the precise point where the shadow of the doorway fell across the threshold, he stopped, sat down, and produced a sound that Max had only heard him make once before, on the trail above the Swannanoa when the storm had still been two days away: a thin, sustained whimper that had nothing to do with pain and everything to do with warning.

“Buddy.” Max crouched. “It’s just the library. You’ve been here before.”

Rufus looked at the dark hallway beyond the open doors and communicated, as clearly as a dog can communicate anything, that whatever was in there now was not what had been there before.