Bashir, Dax and Kira are on a routine biosurvey mission in the Gamma Quadrant when they receive a 200-year-old distress signal. They land on a planet in the Delta Quadrant where the population, once a spacegoing culture, is suffering from a fatal and always painful disease called the Quickening. The disease was inflicted upon them by the Jem'Hadar for defying the Dominion. Death rapidly follows "the Quickening," when red lesions appear all over the victim's body. On the planet surface, Bashir meets a pregnant woman who is determined to live to see her child, and he begins to find ways of treatment. Trevian, a local anesthesiologist who euthanises patients when they contract the disease, is opposed to Bashir prolonging the suffering of his people, and encourages the patients to commit suicide rather than allow themselves to be experimented on. Bashir is not insensible to the pain of the disease, but he does not believe decisions to commit suicide should be reached so quickly. His efforts with the pregnant woman does not go well, and she dies immediately after childbirth. The doctor has not found a cure, but he realizes that the baby is immune to the disease and so finds a vaccine instead. Trevian promises to distribute the vaccine and thus wipe out the deadly disease. Would you know, he saves the whole planet from imminent death! What a doc!