Per 
The Pulsating Heart
Item #: SCP-5250
Object Class: Euclid
Special Containment Procedures: SCP-5250 is to be contained within a titanium case in a standard large-object vault at all times. Any sort of transportation of SCP-5250 must be done in an airtight titanium container. Personnel are to not engage in physical contact with SCP-5250 nor be in the general vicinity of the object.
Any human subject exposed to SCP-5250 must be quarantined, given a LED flashlight, and have their isolation room monitored the same night at all times.
Description: SCP-5250 is a human heart made out of an unknown metallic material measuring 1.35 meters in height and 0.91 meters in width. SCP-5250 releases a set of pulses similarly to an EMP at random given times throughout the day regularly. SCP-5250 also pulsates when any living subject is in the vicinity of the object. SCP-5250's pulses extend up to 20 meters in length. Any living subject struck by a pulse will experience a slight effect of paralysis for a few minutes. The living subject struck by a pulse will then feel an irresistible urge to sleep during midnight leading them into a forced sleep. After the subject has fallen asleep, they will experience a stage of sleep paralysis a few minutes later. While the subject is in this state, the subject will begin to perceive an entity dubbed SCP-5250-2 forming within a certain range approximating from 4 to 12 meters away from their sleeping point.
SCP-5250-2 is a dark shadowy figure that will slowly approach the subject during their stage of sleep paralysis1. Upon reaching the subject, the entity will grab them with its arm, upon this happening the area surrounding the subject will shake and turn pitch black but only for the subject. During the effects of SCP-5250-2, the subject will be transported to an external dimension referred to as SCP-5250-1.
SCP-5250-1 is a pitch dark dimension with an expansive futuristic seeming city that consists of skyscrapers and tall buildings; only the top half of the buildings contain windows that appear as perfect perpendicular rectangular luminous white lights. While in SCP-5250-1, all instances of SCP-5250-2 will lurk around the subject at different distances and mysteriously fade away through the walls and floor; all instances of SCP-5250-2 are hostile at all times. When an instance of SCP-5250-2 gets a hold of the subject in SCP-5250-1, it will enter the subject's body through either the stomach or mouth. Once SCP-5250-2 enters the body, it will start transforming every part of the body into the same substance2 that the instances of SCP-5250-2 and SCP-5250-1 are made up of, starting from the inside out. During the transformation, all organs will be filled with the substance, thus making them deceased and unresponsive. The process of the transformation results in the subject's death and a new instance of SCP-5250-2.
Exiting SCP-5250-1 is rather difficult due to the constant lurking of instances of SCP-5250-2 and because of how the buildings are laid out causing them to create a maze within SCP-5250-1. There are 5 exits in total within SCP-5250-1, with 1 exit at each of the 4 corners while the 5th being in the center of SCP-5250-1. The exit appears to be a black portal with a white outline around the borderline of the portal. 4 luminous white crystals also surround the portal with the portal being in the center of the 4 crystals at all exits. Exiting SCP-5250-1 causes the subject to jolt awake at where their original point of repose was before they entered SCP-5250-1.
SCP-5250 was recovered on 9/23/20██ from a mountain range in Arkansas near the city of [REDACTED]. [DATA EXPUNGED] personnel were lost and never seen again the next day from when SCP-5250 was recovered. Out of all metals, titanium was found the most effective against the object's pulses. It is unknown why titanium diminishes the pulses of SCP-5250.
Addendum: After a series of tests being requested by Dr. Jonathan Rivera, multiple test subjects were exposed to the pulses of SCP-5250.
Test A - March 7th, 20██
Subject: D-268
Procedure: Titanium case for SCP-5250 was lifted allowing the pulses to disperse and affect D-268.
Results: D-268 experienced a weak state of paralysis for a few minutes with no extra side affects. After testing, D-268 was taken back to their cell. The next day, D-268 was claimed missing after security officers checked the subject's cell and the rest of the containment zone.
Analysis: The pulses will cause the subject to experience slight paralysis for a few minutes. The subject will then disappear at an unknown time leaving no traces behind.
After the analysis made, Dr. Rivera decided that subjects exposed to the pulses are to be quarantined after testing and monitored at all times and have a tracker attached to them.
Test B - March 8th, 20██
Subject: D-2075
Procedure: Same procedures followed as test log A with the addition of monitoring the subject at all times after exposure to SCP-5250 and also having a tracker attached to the subject.
Results: D-2075 experienced a weak state of paralysis for a few minutes with no extra side affects as tested in test log A with subject D-268. While D-2075 was being monitored, it was noted that D-2075 vanished during midnight after the subject's body moved strangely to a slight while the subject was sleeping. The subject left no traces behind, and it was noted that the tracker was still attached to the subject at the time of the disappearance of the subject. Tracking of the device attached to the subject failed; both the tracker and subject were lost.
Analysis: It is now confirmed that the pulses affect the subject with slight paralysis for a few minutes. It is noted that the disappearance of the subject occurred during midnight.
Dr. Rivera concluded that subjects will vanish at midnight after being exposed to the pulses of SCP-5250. Dr. Rivera requests 2 test subjects for the next test to confirm the conclusion made. By testing 2 subjects on SCP-5250 it is possible to monitor whether the amount of subjects exposed to SCP-5250 will alter the reactions affecting the subjects.
Test C - March 10th, 20██
Subjects: D-7436 and D-3779
Procedure: Procedures followed in test log B will be repeated for testing.
Results: Both subjects experienced a weak state of paralysis for a few minutes with no extra side affects as tested in the previous logs. Both subjects vanished during midnight after making slight strange movements in their sleep. Half an hour later, subject D-3779 unexpectedly returned to their point of disappearance. When D-3779 appeared, they jolted forward and out of their bed as if they had a nightmare. Monitoring of D-3779 continued for the night. D-7436's point of disappearance was carefully monitored; D-7436 never reappeared and left no traces behind.
Analysis: It is now confirmed that subjects will vanish at midnight after being exposed to the pulses of SCP-5250. There appears to be a chance of the affected subject returning a while later after disappearance. Further research required of the affects experienced from the reappearing subjects.
D-3779 reported feeling extreme exhaustion during the night. D-3779 stated that he was in a state of sleep paralysis for a few minutes after he fell asleep. He also noted that a dark shadowy figure appeared at the corner of his isolation room. D-3779 explained that the shadow approached him and grabbed a hold of him which then caused the place around him to shake and turn pitch black. Once the subject's view returned, he found himself on the floor next to subject D-7436. Both subjects found themselves in an unknown location which appeared to be a entirely different dimension. D-3779 stated that both of them were being stalked by multiple dark figures. These figures according to D-3779 would phase through the floor and walls and continue to lurk around them at different distances. Both subjects found themselves lost and as if they were in a maze made of futuristic skyscraping buildings that have white lights as windows at only the top half of the buildings. D-3779 stated that they encountered multiple dead ends made by the buildings shapes and large pathways that usually lead to more pathways and dead ends. D-3779 said that in one of the pathways, one of the shadows got a hold of his partner and that the shadow entered subject D-7436's body through their mouth. D-7436 was yelling in agony while the shadow turned D-7436's body into the same substance as the dimension and as of the dark figure. D-3779 stated that D-7436 was unresponsive for a minute before converting into a figure that was a replica of the shadows lurking around them. The shadow that was before D-7436 became hostile and started lurking around D-3779. In terror D-3779 began to sprint while being chased in more velocious speeds by the dark figures that lurked around him. D-3779 after running and walking for what he stated that felt like an eternity, spotted a luminous white shine at a certain place which behind it, looked like the void since there was nothing else in distance and he noted that if he fell off it would look like it was infinite. The luminous glow he spotted were from 4 white crystals surrounding a portal with a white outline around the black portal. D-3779 reported seeing his bed and isolation room through the portal. As D-3779 was sprinting and almost caught by the shadows, he jumped through the portal returning to where he was sleeping. D-3779 jolted forward out of the bed as if he was having a nightmare which was captured on footage while D-3779's isolation room was being monitored.
After the reports from D-3779 it was decided that the dark figures named shadows by D-3779 will be referred to as instances of SCP-5250-2; the addition of the dimension named "The Shadow Realm" by D-3779 will be referred to as SCP-5250-1. The explanations given by D-3779 are to do addition to the description of SCP-5250.
After the following test logs, Dr. Rivera requested that the following procedures from test log B are to always be used on exposed test subjects with the addition of giving them an LED flashlight to carry on them after exposure to SCP-52503.
