Item #: SCP-2828
Object Class: Safe Euclid
Special Containment Procedures: SCP-2828 is currently uncontainable and is ubiquitous in global populations. However, risk of breach of security or public discovery is deemed very low, as it is undetectable without the use of strong mnestics.
Undercover Foundation operatives posing as high-ranking employees in pharmaceutical and chemical manufacturing companies are to monitor any projects aimed at production of chemicals with mnestic capabilities, procure prototype batches to test for effectiveness at facilitating perception of SCP-2828, and either halt the research or allow it to continue based on the results. Foundation operatives are to consistently search through Internet posts and scientific journals for anything that might be referring to SCP-2828 and investigate accordingly.
Descriptions of SCP-2828's appearance, texture, sound, odor, or taste are to be tested for safety with D-class personnel by double-blind RAISA or antimemetics department personnel and redacted or expunged accordingly.
Description: SCP-2828 is an antimemetic and nearly undetectable part of the human body located behind the ear. The role of SCP-2828 in bodily systems is virtually nonexistent, and is hypothesized to be fully vestigial.
SCP-2828 can only be perceived through the use of Class-W or stronger mnestics, but only to a limited degree if at all. When it is perceived, it can only be perceived with one sense1. Whichever sense is used to perceive SCP-2828 first by a given subject is the only sense the subject will ever be able to perceive it with. For example, if a subject saw SCP-2828 before he or she felt, heard, smelled, or tasted it, then the subject would not be able to ever feel, hear, smell, or taste it.
This effect extends to all forms of communication; a subject who has seen SCP-2828 is unable to understand a written or verbal description of its smell, descriptions of the sound2 it makes, et cetera. Amnestics are capable of erasing memories of SCP-2828, but the subject will still be unable to use any other sense than the one he or she first used to perceive it to perceive it again. This is thought to be because SCP-2828 permanently alters the brain chemistries of those who perceive it.
A subject who has never observed SCP-2828 under the influence of mnestics can be told and fully comprehend information regarding SCP-2828 that uses more than one sense to describe it. However, if said subject uses mnestics afterwards and attempts to observe SCP-2828 using any sense, [REDACTED]. It is therefore imperative that no Foundation personnel learn of any complex or relatively detailed description of SCP-2828's appearance, texture, sound, odor, or taste (see Special Containment Procedures).
Other than this, SCP-2828 poses no immediate danger and possesses no further anomalous properties.
Addendum 2828-01: SCP-2828 was discovered after Dr. A██████, a Foundation researcher and one of Site-██'s clinicians, was transferred to the antimemetics department in 19██. As with all antimemetics department staff, she began a Class-W mnestic regimen. She continued to act as a Site-██ clinician. Two days later, on ██/██, Dr. A██████ performed a semiannual checkup on Agent F███ and noticed a peculiarity behind his ears. When she touched the area, she was unable to receive any tactile stimulus whatsoever. She touched the same area on herself with the same results. Recognizing the obvious anomalous influence, she contacted Site Director S███████ immediately.
Addendum 2828-02: Following the events of 06/17/19██, all tests regarding SCP-2828 have been suspended by order of Site Director S███████.