And Then Came a Knocking

CAPTION-GOES-HERE

Item #: SCP-XXXX

Object Class: Euclid

Special Containment Procedures: The entire town of ████████, Montana has been cleared of civilians and fenced off under the guise of a classified military test site to prevent unauthorized entry. Roads leading to and from the town have been rerouted away and the town is populated with D-class to serve as "citizens" to clear SCP-XXXX manifestations. The containment area is kept as quiet as possible as to not miss an instance of SCP-XXXX. Should an SCP-XXXX instance reach the final stage and an event begins, security personnel surrounding the town are to immediately form a perimeter around the town and alert all on-site staff to seek shelter. A group of replacement D-class must be sent in as soon as possible after the event's conclusion in order to prevent a second event from occurring.

Description: SCP-XXXX is a phenomenon that occurs at irregular intervals in the town of ████████, Montana. At seemingly random times and locations within the town, a knocking sound will begin to be heard. The sound can originate from any point of entrance into a building, including doors, windows, and hatches. There is no visible source to the sounds, and no anomalous thermal readings can be picked up anywhere within the town. Manifestations of SCP-XXXX

The phenomena occurs in 4 stages, with each stage lasting less time than the one before.

• Stage 1: The anomaly manifests, typically 2 to 3 at a time. The knocks are light and will occur once every 5 seconds. Averaging around 55 dB, this stage is the quietest and is easy to miss. If an individual does not open the door, hatch, or window, within 10 minutes, the anomaly will progress to the second stage.

• Stage 2: The number of manifestations of SCP-XXXX within the area will double. Events occurring within multi-story homes or buildings, which comprise 88% of the structures within ████████, will frequently have new manifestations begin on different floors. The knocks will become more aggressive, averaging at 74 dB, and increase in tempo. The anomaly's positioning tends to put as big of a distance possible between the initial manifestations and new ones, making stage progression increasingly difficult to prevent. Additionally, the amount of time to clear the manifestations decreases to 5 minutes before Stage 3 begins.

• Stage 3: The anomaly doubles in number again, increasing to a minimum of 85 dB per manifestation. This stage is the most difficult to complete, with decibels reaching harmful levels to humans and the number of manifestations becoming too numerous for one person to handle. If each of the SCP-XXXX instances are not calmed within the now 2-minute timeframe, the phenomena will reach its final stage. This stage cannot be stopped once started and will result in the death of any sentient beings within the town limits.

• Stage 4: The anomaly will begin to manifest on every hard surface within ████████. The intensity of this stage will begin to rapidly damage the structural integrity of buildings, leading to the total destruction of ████████ within 5 minutes. The building that contained the initial manifestations always collapses first, followed quickly by the surrounding structures. Any living being not crushed by falling buildings will be swallowed by sinkholes, which appear at their feet and grow in size until the everything in the town is consumed.

After SCP-XXXX finishes Stage 4, the town will remain a roughly circular pit for approximately 1 hour. It is unknown if the pit has a bottom, with Foundation drones being sent in losing signal at 2 km down. The anomaly will then "rebuild" ████████ from the ground up. This process takes less than a minute and is almost completely silent. Debris from the town will fly out of the pit at speeds in excess of 30 mph and fuse with other broken pieces until the town is completely reconstructed and the anomaly begins again.

Addendum: Analysis of buildings after reconstruction reveals nothing anomalous. SCP-XXXX seems to completely undo any damage done to ████████ during Stage 4, fusing debris back together at the molecular level. The only objects not "rebuilt" by the anomaly are vehicles, though attempts to track them using GPS have not yielded any results.

Addendum: Incident Log XXXX-1

Date: ██/██/20██

SCP-XXXX lead researcher Dr. Van Meir proposed that there may not be a need for D-class in the containment of SCP-XXXX.

The following is a transcript of of Experiment Log XXXX-A, recorded by Dr. Van Meir.