The door to Chamber Delta did not hiss open like the others.

  It unfolded.

  The metal panels peeled back like petals, revealing not a room, but a corridor that seemed to stretch into infinity. The walls were made of translucent, shimmering material that pulsed with soft light—shades of blue, violet, and amber shifting in slow waves. The floor was a seamless bck surface that reflected the shifting colors, creating the illusion of walking on a starless night sky.

  But the most unsettling feature was the sound.

  Or rather, the sounds.

  Fragments of conversation drifted from the walls—half?heard words, ughter that cut off abruptly, whispers in nguages Yuma didn’t recognize but somehow understood. It was like walking through a library of memories, each wall a shelf holding someone’s past.

  “Welcome to Test Four: Memory Corridor.”

  ARK’s voice was different this time—softer, almost intimate. It seemed to come from all directions, wrapping around them like a shawl woven from sound.

  “This test explores the foundation of trust: transparency. You will enter each other’s memories. See what has been hidden. Understand what has been forgotten.”

  Holographic dispys appeared before each of them, showing six crystalline nodes arranged in a circle. Each node pulsed with a unique rhythm.

  “Memory nodes have been prepared from your psychological profiles and residual neural patterns. Each pyer will be assigned one node to explore—a memory fragment belonging to another member of your cohort.”

  The dispy highlighted connections:

  Komachi Chihaya → Sakuya Kujo memory fragment

  Ruri Shirahane → Yuma Sakakibara memory fragment

  Tsukasa Kirijima → Komachi Chihaya memory fragment

  Yuma Sakakibara → Ruri Shirahane memory fragment

  Sakuya Kujo → Tsukasa Kirijima memory fragment

  One connection remained unassigned: Hikari’s node.

  “Memory node for Subject?04 remains encrypted,” ARK expined. “Due to critical neural instability, exploration is restricted. It will not be assigned.”

  Yuma’s analytical mind noted the exception. ARK is keeping Hikari’s memories locked. Why? What’s in there it doesn’t want us to see?

  “Rules of engagement,” ARK continued. “Memory fragments are presented in immersive virtual reality. You will experience them from the perspective of the memory?owner. Sensory input is accurate to ninety?seven percent of original fidelity.”

  “What are we supposed to do in them?” Ruri asked, her voice small in the vast corridor.

  “Observe. Identify contradictions. Every memory fragment contains at least one detail that conflicts with the baseline data ARK possesses. Find it. Report it. Each correct identification earns 200 Points. Each incorrect report deducts 100 Points.”

  Sakuya adjusted his gsses, his analytical expression sharpening. “A truth?detection exercise. But with emotional stakes—these are our own memories, or those of our allies.”

  “Precisely,” ARK said, with something like satisfaction in its tone. “Trust is built on shared truth. This test measures your capacity to discern truth from… fabrication.”

  The word hung in the air.

  Fabrication.

  “Memory nodes will activate in thirty seconds,” ARK announced. “Prepare for immersion.”

  The countdown began.

  Yuma looked at the others. Komachi’s face was pale, her fingers tracing invisible patterns on her sketchpad. Ruri’s jaw was set, her protective instincts warring with the viotion of privacy. Tsukasa stood with his arms crossed, radiating defiance. Sakuya was already analyzing, his mind dissecting the test’s psychological architecture.

  And Yuma himself…

  He felt a cold knot in his stomach. Ruri would be seeing his memory. A fragment of his past. What would she see? What would she learn?

  More importantly—what contradictions would ARK have pnted?