|HEART ATTACK WARNING!!! JK, HAVE FUN!|
(D-3456 is a 31-year old Caucasian male of average build. Psychological background is unremarkable. Class-D designation is the result of a demotion due to [DATA EXPUNGED]. D-3456 is equipped with an LED flashlight, a handheld camcorder fitted with a transmission stream, and an audio headset for communication with Dr. ███ at Control.)
D-3456 inserts SCP-860 in the door leading to an abandoned house on ████████████ Street, ██████, Germany. He turns the key and opens the door, revealing SCP-860-1. D-3456 staggers.
Dr. ███: Please proceed.
D-3456 hesitates, then passes through the door. After he takes two steps, a loud bang is heard. D-3456 turns quickly. The door is closed and attached to a large concrete wall. D-3456 moves towards it and attempts to turn the knob.
D-3456: ████, this ████ is locked! How the hell'm I supposed to—
Dr. ███: Please follow the trail, D-3456. The exit should be on the other side.
D-3456 sighs, then turns around and walks down the trail. After walking 64 meters, D-3456 stops.
D-3456: Did you hear that?
Dr. ███: No sound came through the audio feed.
D-3456: It sounded like… a howl… or… or something. Came from the woods, seemed far away.
Dr. ███: A howl? Like a wolf?
D-3456: Not… exactly. Sounded weird. Distorted.
Dr. ███: Please proceed down the trail.
D-3456 starts walking again, with increased speed. After 43 meters, the mist starts to thicken and acquire a deeper shade of blue.
D-3456: It's starting to get really hard to see here. This ███████ flashlight isn't—
D-3456 suddenly starts to turn around.
D-3456: [shouting] ████! ████! Did you hear it now?
Dr. ███: Nothing came through the audio feed, D-3456. What did you hear?
D-3456: [shouting] Same thing as before! Closer! How the ████ didn't you hear it, it was—
Dr. ███: Please continue to follow the trail, D-3456.
D-3456: [shouting] No, you don't get it, it—
A loud roar can be heard coming from D-3456's left. D-3456 screams and starts running down the trail. Every ten seconds, the sound of steps coming from behind D-3456 can be heard, starting off distant and increasing in volume until they appear to be less than one meter from D-3456, at which point they stop.
After running 68 more meters, D-3456 reaches a large concrete wall with a door in it. D-3456 kicks the door open, revealing the main hall of the abandoned house. D-3456 enters, turns around and closes the door. Two minutes later, he opens the door again, revealing ████████████ Street. D-3456 shows extreme paranoia for the following weeks, claiming to hear the same howl in the distance when alone. Effects seemed to fade after ██ weeks. D-3456 now behaves normally.
Close analysis of the audio feed revealed that a very low sound could be heard the second time D-3456 stopped. The sound file containing the amplified sound can be found here:
SCP-860, when used on any door, it reveals this forest.