The Brain Parasite That Wants to Take Over Earth - SCP 3003

SCP-3003-2 is a single-celled organism found in SCP-3003, which can infect humans and cause changes in their behavior and thinking. Those infected develop an obsession with the well-being and spread of SCP-3003-1, as well as a pleasure response to stimuli related to it. They also possess above-average reasoning capabilities, and emotions are suppressed. SCP-3003-2 cannot reproduce within humans and most cells die within 30 days. Infusions of SCP-3003-2 or implantation of SCP-3003-1 are necessary for continued presence within the human body. SCP-3003-2 is not found in wild populations of SCP-3003-1, but in captive populations exposed prior to introduction to humans. Full recovery occurs within two years of the death of all cells.