Following the dissolution of Foundation/GOC Joint Task Force 2861-Omega "Ragna-blök", the dimension that held SCP-3███ (hereafter DIM-3███) remained accessible to Foundation personnel via Dimensional Site-712. The original SPIDER1 rift was opened aboard the sinking GOC Airship 'Legacy', by Eta-5 CO Sanders after the neutralization of SCP-3███.
Testimony provided by surviving members of MTF Eta-5 "Jäeger Bombers" indicated that an entity located somewhere within DIM-3███ had attempted to initiate an XK-Class Scenario.2 An exploration was proposed by Eta-5 Alpha CO Sanders, which was authorized by Jelani I████████3.
Four Class-R Aerial Drones (C-RAD-1-4) were deployed through the rift at Dimensional Site-172. Upon entry into DIM-3███, each was piloted in a different cardinal direction. Their cameras displayed an apparently endless ocean, covered in a thick layer of fog. Twelve hours after entry, C-RAD-3 came upon a large landmass (consisting of a mountainous taiga overlooking the coast) hidden by the mist. C-RAD-3 landed, and activated its installed SPIDER.
C-RAD-1,-2 and -4 continued their flight paths, continuously filming open ocean for several more hours; until their power supplies had expired. The SPIDER unit aboard the Legacy became submerged at this point and ceased function.
Exploration Log Day 1:
Notes: The exploration team consisted of:
Upon entering DIM-3███, the rift was sealed from the Site-712 side, to prevent a possible breach of unknown entities into Foundation-owned extra-dimensional space. This rift was to be opened once every 48 hours to facilitate communication.
The team canvassed the area within a 3 sq. km. radius of the entry point, coming across a large boulder half-buried in the sand. A rope of indeterminable composition was tied to the slab, hypothesized to be the very same chain that SCP-3███ had been restrained with.
Dr. Romanov attempted to retrieve a sample of the luminescent, cerulean substance coating the frayed end of the chain, however the substance proved to be anomalously caustic and destroyed all equipment that came into contact with it.
Night fell instantly during their survey of the rock, prompting an early return. During the trek back to the Provisional Site, D-857 and D-128 claimed to hear melodic singing emanating from the woods. Agent Wu-Cheng corroborated their claims. Later that night, Agent Wu-Cheng abandoned his post on watch, absconding alongside said D-Class.
Exploration Log: Day 2
Notes: A ring of standing stones, covered in runic inscriptions, was discovered 5 km. North of the entry point. Dr. Matteus approached the stones to investigate the markings. She was subsequently shot by D-128; who had been lying in wait nearby, having somehow procured Agent Wu-Cheng's sidearm. Agent Matteus stumbled within the circle, and vanished. D-128 was terminated by the remaining squad members.
Minutes later, Agent Matteus reappeared outside the stone ring, claiming to have found traces of the same luminous substance from earlier. It was at this point CO Sanders returned to Dimensional Site-712 to submit a progress report. Agent Matteus had only received a glancing blow, and declined to return to Site-712 for medical attention.
Exploration Log: Day 3-6
Notes: Sanders did not return when the rift was opened on 4/18 and 4/20.
A Search and rescue mission is currently underway, as of 4/21/2███ This mission has been cancelled, personnel have been recalled and further exploration has been suspended indefinitely. See Document: DIM-3███-A: Recovered information for more details.