After a bride-to-be becomes violently ill at her bridal shower in Philadelphia, Dr. Connor and his NIH team glove up and suspect a lethal form of anthrax is in play as more patients pile up -- and unless they quickly connect the dots to the source, a local newspaper will publish a news story that could terrorize the entire city. As Connor, Dr. Durant and their crew get vaccinated, they suspect the victims somehow came into contact with tainted animal products, and a sickly Nigerian man could provide their best clue.

When a 10-year-old girl is found deathly ill from lack of healthy bone marrow, Dr. Connor and the NIH team work feverishly to keep her alive long enough to find a family member who would make a worthy marrow donor. Unfortunately, her adoptive parents just died days before, so Eva makes it her personal mission to find the adrift child's biological mother. But the case's urgency intensifies when others in the same area fall ill from the identical aplastic anemia while Eva struggles to convince the girl's reluctant real mom (as Cyndi, guest star Catherine Wadkins) to help save the abandoned daughter she wants to forget.