SCP-661

Item #: SCP-661

Object Class: Safe

Special Containment Procedures: SCP-661 has been marked with a yellow warning sign by the Foundation. The laboratory where SCP-661 is held is currently under constant video surveillance, and all personnel entering the room are to be photographed and drug tested before entering. Any personnel found to be in possession of more than 0.3 micrograms of SCP-661 on any given day will be immediately terminated for security reasons.

A large locker in the same room stores samples of normal atoms present in the environment around the facility, with samples from previous days kept in an identical locker located on the other side of the room. This room should not be entered except by Class 3 clearance or above.

Description: SCP-661 is the radioactive version of neutronium, an extremely rare element. Its anomalous properties manifest when more than 0.3 micrograms of SCP-661 are present in the bloodstream of any individual at any given time.

The effects that occur due to this exposure vary with each exposure, but always involve others; anyone in physical contact with SCP-661 will undergo some form of mutation before dying within three days. The exact nature of these mutations depends on the amount of exposure to SCP-661, but they always include the following:

SCP-661's effect on non-human organisms is significantly reduced, causing only minor changes to their appearance and behavior patterns. These changes are not noticeable unless close examination is conducted for several years, and have been recorded as early as ██ days after exposure.

When the subject dies, a new instance of SCP-661 takes 106 seconds to form. This law appears to apply regardless of whether the subject was human or not. Existing instances are destroyed by normal disintegration after one hour, but if they run out of matter they continue to exist as a pure mass of radiation resistant to all known types of damage.

Addendum 661-1: Discovery and Acquisition

SCP-661 was created in a ████████ nuclear reactor, where it was the byproduct of several nuclear fission reactions. Its anomalous properties were not noticed until several months later, when several lab animals were found to have died. Further testing revealed that the animals were being mutated by SCP-661 before their deaths.

When this evidence was presented to the Foundation, it was decided to use SCP-661 for research purposes. It is recommended that further tests be carried out on any individuals exposed to SCP-661 for more than two days at a time.