Per 
Item #: SCP-XXXX
Object Class: Safe
Special Containment Procedures: Personnel seeking to enter SCP-XXX must adhere to strict psychological screening upwards of twenty-four hours before contact with the entryway to Site of SCP-XXX. Staff or D-Class with a history of psychological illness or currently undergoing therapy ( in the case of Site Staff ) are to be barred entry forthwith.
Any and all personnel within the outlying area of SCP-XXXX must be equipped with a standard issue radio device and GPS broadcaster - in the event of a Displacement Event1, personnel within SCP-XXX must activate their GPS device within their fifteen minute allotment.
Should a Displacement Event occur, field agents located at common re-materialization zones must be alerted immediately to maintain standard containment procedure.
Personnel must not exceed the fifteen minute duration on entry to SCP-XXX. Any individual within SCP-XXX after their allotted time is to be considered lost by Site Staff.
Description: SCP-XXX refers to a pair of approximately 30 metre joint corridors presently located in █████, ████████ High School within the Southern Highlands of Scotland. SCP-XXX is closely associated to an anomalous hazard that occurs within fifteen minutes of a subject entering one half of the twin corridors. Each half of SCP-XXX presents itself as a seemingly innocuous ( if empty ) version of a corridor native to its present environment.
The hazard makes itself known when a subject enters SCP-XXX-1 and remains for a period of fifteen minutes, wherein any entryway to SCP-XXX-1 closes and locks. At the date of writing, ██-██-2███, no known ballistic force or explosive has proven capable of gaining entry to SCP-XXX once its anomalous properties manifest.
After fifteen minutes have elapsed. subjects within SCP-XXX-1 indicate a sudden and acute awareness of SCP-XXX-3 in the adjacent corridor of SCP-XXX-2.
SCP-XXX-3 has yet to be adequately described or seen by members of Site Staff or D-Class personnel.
Any subject within SCP-XXX-1 that become aware of SCP-XXX-3 are universally afflicted by a sudden and erratic fear that the entity means them immediate harm. Three minutes after SCP-XXX-3's emergence, subjects report that it has begun to "run" towards them from down the length of SCP-XXX-2. Though no such action has been visually sighted, communications devices granted to D-Class subjects have fed back sounds synonymous with that of rapid footfall.
Light sources within SCP-XXX-1 will at this stage cease to function, and subjects indicate a strong desire to leave SCP-XXX-1 as swiftly as possible. After thirty minutes of continued activity from SCP-XXX-3, the subject will begin to shown signs of self-harm or suicidal tendencies where none were present before. These habits have been expressed as an attempt to "escape" SCP-XXX-3.
SCP-XXX-3 will continue to draw closer without reaching SCP-XXX-1 until the point of any subject's expiration. It will then cease all anomalous functions and the door to SCP-XXX-1 will open.
At an unspecified period, SCP-XXX will relocate to one of five fixed locations, typically within the same geological circle with a noticeable preference for schools, hospitals and nurseries - as of ██-██-2███, seven such Displacement Events have occurred since containment.
Addendum: Any and all tests involving multiple D-Class subjects within SCP-XXX-1 are to be suspended, pending O5 approval as of ██-██-19██.
