rating: +134+x
Item#: 4431
Containment Class:
Secondary Class:
Disruption Class:
Risk Class:


Bannard expedition photograph; unlabeled.

Special Containment Procedures: Research Station-05 has been built directly above SCP-4431-A. Seismometers across Antarctica will monitor activity from SCP-4431-A and report any irregularities in the anomaly's behavior. At least one boring probe and an ice sheet drilling mechanism are to be kept at the station in the event that investigation of SCP-4431-A is necessary.

Contact is to be maintained with all Foundation and non-Foundation research stations in Antarctica for reports of SCP-4431-B manifestations. If a manifestation is reported, personnel at the station are advised to monitor the manifestation and resultant SCP-4431-C instances. Objects left by expired instances are to be transported to the nearest Foundation facility. Mobile Task Force Xi-1 ("Dispatch from Miskatonic") will be deployed for containment if necessary. Non-Foundation personnel that witness these anomalies will be administered appropriate amnestics on leaving Antarctica.

Cover stories regarding the Dayton Bannard Antarctic expedition have been disseminated, reporting the expedition's ship as having vanished en route to the Filcher Ice Shelf. As surviving personal accounts from Bannard describe a wide variety and number of anomalous phenomena beyond SCP-4431, all information on the expedition has been acquired by the Foundation.

Potential links between the events of the expedition and SCP-4431-A's current activity are of high concern.


Overhead view of Research Station-05 in the Antarctica Plateau.

Description: SCP-4431 designates two subterranean artificial structures (SCP-4431-A and SCP-4431-B) and a collection of psionic organisms (SCP-4431-C) present in East Antarctica.

SCP-4431-A is a machine located 3,400m below the Antarctic Plateau1, buried in the bedrock under the East Antarctic Ice Sheet. The object's depth renders it undetectable by ice-penetrating radar, preventing full analysis of its appearance and size. Current size estimates include a minimum width of 20km. As drilling investigations to examine the structure invariably end in failure (refer to Discovery), no further information on SCP-4431-A is known.

SCP-4431-B is a cylindrical tunnel constructed from a rhodium-platinum alloy, with a 11m interior radius. The tunnel extends for 39m before reaching a sharp vertical drop, which descends for a distance estimated to be a minimum of 3,000m. SCP-4431-B will manifest in a region of the Antarctic Plateau on a bimonthly basis, rising out of the terrain until a majority of its entrance is exposed.2 A variable number of SCP-4431-C instances will then exit, often between one or seven. After a period of time ranging from eight hours to three days, SCP-4431-B demanifests, retracting into the ground. Connection with tracking devices placed on the structure during demanifestation are all lost after two hours, preventing observation of SCP-4431-B's relocation.

The body structure of SCP-4431-C instances can vary, though consistent details have been determined. These details are as follows:

  • 1m tall upright conical bodies, with the main body and each limb segmented in a manner similar to arthropods. The main body is divided into three sections.
  • Four or more legs attached to the base of the body.
  • Variable numbers of 3m long tendrils on the body's midsection, each ending in a claw.
  • A toroidal mass covered in small, unknown biological structures, affixed around the top of the body. Presumed to be a form of sensory organ.
  • A set of mandibles on the bottom of the cone.

Anatomical deviations tend to include features that aid in withstanding Antarctic conditions or other purposes. Tumorous growths acting as heat radiators have been observed, along with cybernetic flamethrower implants. Many instances possess conical protrusions on their body, which open to dispense environmental monitoring devices.3 Rarely, instances are found with the tops of their bodies replaced by antennas and clusters of spherical machinery that serve similar purposes.

Following SCP-4431-B manifestation, SCP-4431-C instances will attempt to construct makeshift structures from any surrounding materials, presumably intended to be shelters. Instances typically expire in a few hours from environmental factors, though ones brought into containment have average lifespans of 11 hours. Primary cause of death is the gradual degradation of internal organs. Following this, all organic matter on the instance dissolves into a bright pink fluid (hereafter referred to as haemorozin).

Instances possess psionic abilities, used for the manipulation of objects, surroundings, and entities. Limited telepathic communication has been displayed on occasion.

Information on the suspected origins of SCP-4431 is restricted.



The first reports of SCP-4431 are from 1919, when an Antarctic expedition lead by former British naval officer Dayton Bannard repeatedly encountered SCP-4431-B and SCP-4431-C instances (refer to Addendum.4431.1). Accounts of SCP-4431-B manifestations continued after the first Antarctic research stations were established, leading to SCP-4431-B and SCP-4431-C being classified as anomalies in 2000.

SCP-4431-A came to the attention of the Foundation in March of 2019, when Foundation personnel operating at Research Outpost-02 in the Antarctic Plateau detected abnormal seismic activity originating from an underground location. Based on Foundation simulations of Earth's tectonic plate movement, it was determined that this could be the possible location of a ring-shaped lake depicted on SCP-2651-A, presuming it was not destroyed by geologic activity and prehistoric K-Class events after ~700 million years. Plans for excavation were proposed when the source of the activity triangulated to a region 10km in radius.4


The boring probe and initial borehole.

In June of 2019 a specialized boring probe was sent through the ice sheet and drilled into the bedrock, attaining a depth of 3,400m before entering a cavern with an oxygen-rich atmosphere and contacting a metal surface. Images from the probe show the surface to be covered in an array of mechanical appendages that were in the process of excavating the cavern ceiling. All readings from the probe were lost an hour after contact. Retrieval attempts failed due to the sudden collapse of the sub-bedrock section of the borehole and the formation of frozen haemorozin within the main drilling mechanism. All subsequent drilling investigations have experienced similar outcomes.

SCP-4431-A was registered as an anomaly in August of 2019. Of note is that, since the first drilling investigation, the number of recorded SCP-4431-B manifestations has increased.


Dayton Bannard Journal Excerpts

The following are relevant excerpts from the personal journal of Dayton Bannard, written during his expedition to reach the South Pole. Bannard failed to keep dates for a majority of entries; the excerpts are suspected to have been written during spring of early 1919. Recovered photographs are included.

The journal and photographs were discovered after MTF ξ-1 located the "tank" vehicle of Bannard and the remaining crew in July of 2000, 11km away from the South Pole. Although the tank had retained power and heating due to its anomalous power source, one of the treads had been heavily damaged and prevented continued movement.

Inside the tank was the decayed cadaver of a male human, who had expired from repeated penetrations on the body, matching those caused by an ice axe. The identity of the cadaver has not been determined.

The fate of the Bannard crew is unknown.


South Pole Incident

On 20/09/2019, severe seismic activity occurred at the site of the Geographic South Pole. The Amundsen-Scott South Pole station only experienced minor damages, but its crew reported the emergence of an unknown rocky spire, 51m from the station. Foundation assets were scrambled to the area.

Excavation of the rocky spire found that it extends for an approximate depth of 40m into the Antarctic Plateau. However, fragments composed of its material extend for far deeper, with the lowest at a depth of 110m. It is considered likely that the fragments stretch to the Antarctic bedrock. The upper portion of the spire contains the remnants of a tube similar to SCP-4431-B, though at a width at which a human individual could fit inside with moderate difficulty. Broken pieces of an ice axe blade surround the tube, and a bloodied coat is embedded into the spire nearby.

A compacted soil-like substance, designated SCP-4431-D, comprises the spire. Materials such as ice and rock that come into contact with SCP-4431-D are gradually converted into further SCP-4431-D. The means by which this is achieved are unclear, but are presumed to involve alterations to the subatomic structure of contacting materials.

Visual details match those of the soil described in Bannard's journal. Trace amounts of human gene sequences have been found within the compounds.

The excavation of past sites of SCP-4431-A seismic activity is considered a high priority.

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