SCPG-015: The Tenement Echo

Object Class: Euclid (Potential Keter)

Special Containment Procedures: The "Brighton Apartments" building (Provisional Site-015) located at [REDACTED], Chicago, Illinois, is under permanent quarantine. A two-block radius exclusion zone, maintained under the guise of structural instability and environmental hazard, is enforced by MTF Delta-5 ("Front Runners") and local law enforcement liaisons. All entrances and windows of SCPG-015 have been sealed with reinforced steel and concrete.

No personnel are to enter SCPG-015 outside of approved exploratory or containment missions. Any such missions must be undertaken by Mobile Task Force Tau-4 ("Ghostbusters"), equipped with Class-V auditory dampeners, full-spectrum visual recording devices, reality anchors, and experimental psycho-acoustic weaponry. Personnel must operate in teams of no less than four. Any team member exhibiting signs of auditory hallucination, paranoia, or unprovoked aggression is to be immediately sedated and extracted.

Continuous seismic and auditory monitoring is in place around SCPG-015. Any significant increase in anomalous activity, particularly attempts by SCPG-015-A instances to manifest outside the building's perimeter, will trigger Protocol Nightingale-Echo, involving localized deployment of wide-spectrum sonic disruption charges.

Description: SCPG-015 is a five-story apartment building constructed in 1928. The building itself exhibits significant spatial and auditory anomalies. Internally, the layout of SCPG-015 is inconsistent and non-Euclidean, with hallways that loop, rooms that change location or dimensions, and staircases that lead to previously non-existent floors or dead ends.

The primary anomalous manifestation within SCPG-015 is the presence of multiple hostile incorporeal entities, collectively designated SCPG-015-A. These entities are primarily auditory in nature, manifesting as disembodied voices, screams, whispers, and complex soundscapes that can induce severe psychological distress, paranoia, and violent behavior in human subjects. SCPG-015-A instances can also exert limited telekinetic force, capable of moving objects up to 50 kg, slamming doors, and causing localized temperature drops.

Visual manifestations of SCPG-015-A are rare and fleeting, typically appearing as shadowy humanoid figures or distorted reflections. Direct, prolonged visual contact is reported to intensify their aggression. The number of distinct SCPG-015-A instances is unknown, but auditory analysis suggests at least two dozen unique vocal signatures.

SCPG-015's anomalous properties appear to be "feeding" on ambient sound and emotional distress, growing more potent and aggressive during periods of high activity or when living subjects are present within its confines.

Addendum 015-1: Discovery SCPG-015 came to Foundation attention following a series of increasingly bizarre emergency calls originating from the Brighton Apartments over a 72-hour period in October 20██. Reports included tenants hearing voices, objects moving on their own, and neighbors attacking each other without provocation. The final transmission was a garbled scream before all communication ceased. Local police entering the building encountered extreme auditory phenomena and two officers suffered acute psychotic breaks. Foundation assets intervened, evacuating the immediate area and establishing initial containment. All 37 residents of the Brighton Apartments are presumed deceased or absorbed by the anomaly.

Addendum 015-2: Incident Log 015-Alpha (MTF Tau-4 "Ghostbusters" - Initial Incursion)

Date: ██/██/20██ Team: Tau-4 Alpha (Commander Rex, Operative "Echo" Li, Operative "Static" Jones, Operative "Silence" Miller) Objective: Initial reconnaissance, assess threat level, attempt to locate source of anomaly.

[00:05:00] Tau-4 Alpha breaches main entrance. Building interior dark, air heavy. Immediate auditory phenomena: faint, overlapping whispers in multiple languages. [00:15:00] (Li) "Commander, getting spatial distortion on Floor 2. Hallway seems... longer than the blueprints." [00:17:00] (Rex) "Confirmed. Static, any readings?" [00:17:30] (Jones) "EM fields are fluctuating wildly. Psycho-acoustic energy spiking. Something's aware of us." [00:22:00] Loud crash from Apartment 3B. Team approaches cautiously. Door slams open. Room is empty, but furniture is overturned. A child's laughter echoes, then distorts into a guttural snarl. [00:28:00] (Miller) "Contact! Shadowy figure, west corridor, moving fast!" [00:28:15] Gunfire. Miller fires three rounds from his psycho-acoustic rifle. Figure dissipates. A wave of intense auditory assault hits the team – screaming, metallic grinding. Li and Jones clutch their helmets. [00:29:00] (Rex) "Fall back! Deploy sonic dampener!" Rex activates a localized sonic disruption charge. The auditory assault lessens. [00:35:00] Team attempts to ascend to Floor 4. Stairwell shifts. What was previously a landing now opens into a vast, dark space resembling a dilapidated ballroom, not present on any building plans. Multiple SCPG-015-A vocalizations converge. [00:41:00] (Jones) "They're trying to separate us! I'm seeing... my mother? No, it's not her!" Jones fires wildly. [00:41:30] (Rex) "Static, get a grip! That's the memetic effect! Silence, cover him!" [00:43:00] Multiple shadowy figures converge on Jones. Operative Li deploys a wide-dispersion sonic pulse, staggering the entities. Miller drags Jones back. [00:48:00] (Li) "Commander, the temperature just dropped 15 degrees. I'm picking up a dominant entity signature... it's strong. Coming from the ballroom's far end." [00:52:00] A large, vaguely humanoid shadow, coalescing from smaller forms, rises from the far end of the "ballroom." It emits a deafening roar that cracks Miller's helmet visor. All team members' recording equipment experiences severe interference. [00:52:30] (Rex) "This is too much! Mission abort! Pop smoke, fall back to extraction point! All units, suppressive fire!" [00:53:00 - 00:58:00] Tau-4 Alpha engages in a running firefight, retreating through shifting corridors. Multiple SCPG-015-A instances attempt to block their path, throwing debris and manifesting directly in front of them. Operatives utilize psycho-acoustic weaponry and concussion grenades. [01:02:00] Team reaches ground floor. Main exit is blocked by a newly formed brick wall. [01:02:30] (Li) "Commander, breaching charge on the west wall! It's our only way!" [01:03:00] Li plants explosive. Wall breached. Team exits SCPG-015 under heavy auditory assault. [01:05:00] All members of Tau-4 Alpha successfully extracted. Operative Jones requires immediate medical and psychological treatment for acute memetic exposure. Equipment damage moderate.

Post-Incident Analysis: SCPG-015 is significantly more aggressive and adaptable than initial reports suggested. The spatial manipulation capabilities are extensive. The presence of a dominant, powerful entity or a collective consciousness is suspected. Further incursions will require enhanced countermeasures and a revised tactical approach. Reclassification to Keter is under consideration.