Winch system assembled on Wakoe County Public Recreation Complex pool lip without incident. A SCP-3374-1 carcass returned from autopsy is affixed to bottom of cage. Observation team lowers cage system into pool, and both D-Class personnel, outfitted with standard scuba diving apparatus, swim into cage and secure it.

Winch continues to lower cage. SCP-3374-1 carcass passes through pool floor without incident, followed by cage and D-Class personnel.

Although the cage was outfitted with a pressure sensor that would abort the dive if pressure climbed to dangerous amounts, this sensor was never activated.

Feedback from D-Class video systems indicate the cage is descending through an expansive area of water, possibly an ocean. The Wakoe County pool is still visible as a rectangle of light directly above the cage, surrounded by water. Light conditions appear to decrease rapidly with depth, and darkness below the cage obstructs any visibility of an ocean floor.

The cage continues to descend without incident for several hours. Shoals of unrecognizable SCP-3374-1 are visible in the distance. None of the SCP-3374-1 appear to be hostile.

At the 500m mark, D-Class are instructed to switch on their head-mounted flashlights. Subjects joke about poor visibility conditions.

At the 975m mark, mission control asks D-Class to confirm that there is no ocean floor in sight, and after confirmation, prepares to begin raising the cage after completion of full 1km dive.

At the 982m mark, cable is violently severed by an unseen force. Subsequent examination of remaining cable has indicated that it was cut at a point approximately halfway between the D-Class and the floor of the pool, with shearing patterns indicative of bite marks. Video feed is maintained with D-Class subjects, who visibly begin to panic as the cage continues to descend.

After reassurance from mission control and private agreement, D-Class agree to remain in the cage.

At approximately 2.5km, visibility is entirely dark in every direction. Bioluminescent organisms can be seen in the distance, and both D-Class decide to turn off their flashlights in order to “stay safe.”

At approximately 3.5km, cage comes to rest on the ocean floor. Following conversation with mission control, D-Class switch on flashlights and exit cage. Ocean floor appears to resemble that of terrestrial oceans, with large patches of seaweed visible ahead and to the left.

After further conversation with mission control, D-Class agree to separate and travel in separate directions for 30 minutes before returning to the cage, in the hopes of completing their original mission before extraction. D-5███ heads north, into the seaweed, while D-7███ heads south.

D-7███ quickly reaches a wide, sandy basin, where she finds several objects of interest which she describes to mission control; most notably a rusted artifact tentatively identified as the wheel of an early 20th-century plane, the decomposing and partially consumed carcass of what appears to be a terrestrial whale, and a tattered boxing glove. Moving beyond the basin, D-7███ discovers a network of pillars leaning against each other in regular patterns. Shortly after entering the network, D-7███ is assaulted by a SCP-3374-1 instance resembling a 2m long Olenoides nevadensis with multiple anthropomorphic faces. Video feed is cut and D-7███ is presumed terminated.

D-5███ continues through the seaweed without difficulty until reaching a steep escarpment of sand. An unseen material at the top interferes with D-5███’s flashlight, producing reflections. After conversation with mission control, D-5███ is instructed to climb to the top of the hill. The obstruction appears to be a uniform barrier, stretching up and in both directions beyond the range of visibility. D-5███ is instructed to walk parallel to the barrier before approaching it and does so for 12 minutes without discovering any sort of termination or deviation in the barrier’s surface.

Upon learning of D-7███’s presumed death, D-5███ panics and approaches the barrier despite the wishes of mission control. Barrier is confirmed to be similar to glass in appearance and texture, with no detail visible beyond.

Still visibly distressed, D-5███ locates their diving knife and attempts to forcibly break the barrier. Minor cosmetic damage is observed, but no damage is done to structural integrity.

D-5███ complains about hearing a "heavy thumping", though no corresponding audio is picked up on the video feed. An ovoid silhouette appears beyond the barrier, becoming gradually larger and more distinct. D-5███ states that "five blinking lights" appear to be discernible at the top of the approaching silhouette.

A large three-pronged appendage strikes the barrier, producing minor tremors in the ground. D-5███ retreats into the seaweed. Mission emergency-aborted by the Foundation Regional Administrator, and video log terminated.

END OF LOG