Dr. Connor and Frank are taken prisoner by rebels in a Central American country devastated by a meningitis outbreak and a recent earthquake.
A massive earthquake and a murderous jungle insurrection endanger Dr. Connors and the team when they fly to a violent Central American country to combat a mysterious illness.
When a lobbyist and a Capitol Hill police officer contract a mysterious disease, Dr. Connor and his team suspect a terrorist plot until the leader of a known prostitution ring displays the same symptoms.
When a mysterious contagion puts paramedic Carlos (Anthony Ruivivar) and his patient, a suspect, in the ICU, Dr. Conner and detective Yokas (Molly Price) search for a robbery accomplice, hoping to find the source of the disease.
Connor splits the team to respond to two emergencies -- one a series of miscarriages on a military base hospital, the other a cluster of spontaneous paralysis among people who worked near the World Trade Center prior to Sept. 11, 2001.
The team probes evidence of a strange plague near Baltimore, tentatively linking it to infected police officers and a fugitive, until two children also exhibit symptoms of the contagion.
Conner and his team are called to a frozen Arctic science station to find the cause of a deadly brain affliction that climaxes when its victims suffer from dementia.
When most members of a family come down with a fever and skin rash, Connor and Durant discover they have smallpox, and a rogue scientist is suspected of having unleashed the virus.
Dr. Conner and his team begin to suspect nearby seals of playing a part when a surfer and a volleyball player contract a mysterious disease in a seaside town.
Dr. Connor and his team desperately search for a common denominator when a flesh-eating disease quickly spreads throughout a Maryland hospital.
The team suspects a sexually transmitted disease to be the culprit when adult-film stars begin to die of a strange respiratory illness, but when a suburban mother falls victim to the same symptoms, the search for the contagion begins anew.
A 10-year-old girl is diagnosed as having aplastic anemia, and the team seeks her biological mother for a bone-marrow transplant, then several other people in the area fall victim to an identical strain of the disease.
Dr. Connor and team search for a common link between victims when a mutating and contagious virus kills 10 percent of a West Virginia town's citizens.
Dr. Connor and team suspect a lethal strain of anthrax connected to a local newspaper is to blame for a slew of violently ill patients.
Several college football players fall victim to a mysterious nerve disease, but when the sorority sisters become sick as well, the NIH team must find the missing link before a horde of alumni arrive for the homecoming game.
When children in a remote town begin to suffer deadly muscle inflammation and joint pain, the NIH team targets a local chemical plant as the prime suspect until Natalie discovers another common denominator -- in vitro fertilization.
Dr. Connor walks a political tight-rope when he quarantines an entire island where vacationers are dying from an unknown respiratory illness.
When four Iraq War veterans die from a pulmonary disease, Dr. Connor suspects Gulf War syndrome until the disease is connected to elderly members of a convalescent home.
Four teenage girls in St. Louis contract encephalitis, and the NIH team searches for the source of the infection; Natalie feels powerless to help a patient participating in a long-term clinical trial.
A mysterious and deadly illness turns victims blue and the NIH team is called in to search for the source of the epidemic.