A deadly bacterium from the alien probe infects a Taelon scientist named Ne'eg, who quickly dies from it. The pathogen also turns out to be able to infect humans as well. A white supremacist group steals a sample of the bacterium and uses it to infect a community center. Boone, Da'an, Lili, and Dr. Belman end up being trapped in the community center, working on finding the cure before everyone dies. The Taelon mothership places a quarantine field around the building, but it's too late as the airborne disease has already spread to the mothership and several cities in the US. It's only a matter of time before it grows out of control and wipes out both races. Boone decides to use his CVI to speed up his metabolism and allow his body to develop antibodies before he succumbs to the infection. His heart stops, but Da'an uses his energy to revive him. Boone succeeds, and Dr. Belman injects the antibodies into a dozen other people to quickly produce more, before sending the cure to be distributed to the population before a critical mass is reached. She also synthesizes a version of the cure for the Taelons. Doors has Dr. Park modify the bacterium to be deadly only to the Taelons and to keep it secret from the others.
- Fantastic Racism: Shown alongside ordinary racism. Zo'or is clearly of low opinion of human scientists and refuses Kee'sha's suggestions of bringing in human scientists to help him find the cure.
- Find the Cure!: The entire episode is focused on seeking a cure for a bacterium designed to kill Taelons and humans. Boone finally manages to do it by speeding up his metabolism with his CVI, allowing his body to generate the correct antibodies before succumbing to the disease.
- Master Race: The white supremacists are emboldened by the presence of the "white" Taelons, whom they view as proof of their beliefs, and attack a community center in a minority neighborhood. One of the group's members, a scientist, steals a sample of the bacterium from Kee'sha's lab and uses it to infect everyone at the center. By the end, though, the group's leader's son grows disillusioned with his father's ideas and decides to help out at the community center. The group's leader, meanwhile, is clearly hesitant to be receiving the cure taken from the blood of the community center's black leader. The same is true of Zo'or, who is disgusted to be receiving a cure generated from Boone's body.
- Quarantine with Extreme Prejudice: One of the epidemiologists suggests sterilizing the community center, even though it's already under quarantine. It proves to be a moot point, since the disease has already gotten out.
- Synthetic Plague: The probe synthesizes a bacterium specifically designed to kill all Taelons and humans. At the end of the episode, Dr. Park modifies the bacterium to be deadly only to the Taelons.