In the first year of the Enterprise-D's mission, a virulent epidemic strikes the populace of Archaria III, endangering the lives of thousands and provoking acts of violence against those believed responsible for the spread of the disease.
A virulent plague has stricken Terok Nor, striking down both the enslaved Bajorans and Cardassian oppressors, who blame each other for the growing epidemic. Dr. Pulaski must work with Gul Dukat and Kira Nerys to discover the true source of an infection that threatens them all.
An artificial virus has infected the entire Romulan ruling family. Ambassador Spock must put aside his efforts at unification to summon his old friend, Dr. McCoy, who discovers that the only hope for a cure lies with a long lost Romulan heir.
A planet in the Demilitarized Zone, now controlled by the Cardassians, has been stricken with the same deadly disease that has plagued the Alpha Quadrant for years, and only Tom Riker can get the medical supplies the Maquis so desperately need.
Picard joins forces with Captain Mackenzie Calhoun of the Starship Excalibur to track down and confront the hidden architects who unleashed a string of deadly biological weapons throughout the Alpha Quadrant.
While Picard, captain of the USS Stargazer, struggles to keep the peace between two alien races, Lieutenant Commander Jack Crusher must team up with a Vulcan officer named Tuvok to uncover the hidden architect of the attacks.