CLASSIFIED DOCUMENT Y2OR5W-echo-12. Eyes only: clearance omega-7 required. Anomalous structure "Erebus-4" materialized in rural Kyrgyzstan on 02/15/1987, persisting for 47 minutes. Description: labyrinthine citadel with walls that fluctuated between iridescent mist and solidity. Witnesses reported aural hallucinations of grinding machinery and olfactory sensations of burnt copper. Post-event analysis revealed localized distortions in spacetime, suggesting Erebus-4 was a nexus of intersecting chronology fractures. All records of the incident have been excised from public archives. Personnel involved in the investigation have been reassigned to remote postings. Further inquiry is strictly prohibited.