Geneticist David Sandstrom is the chief scientist at the prestigious North American Biotechnology Advisory Commission. The virology/micro-biology NorBAC laboratory is a joint enterprise between the USA, Canada and Mexico that investigates problems of a scientific nature, such as bio-terrorism, mysterious disease and radical environmental changes.

NorBac has finally found Patient Zero, a baby girl named Miranda, and must proceed with interrogations at "Hazmat City." Was this an act of bioterrorism? Caroline is determined to find out who's responsible as more die and one more is exposed. Mick turns to Lilith, who helps him steal evidence from the scientist who cloned him, his own father.

Caroline suggests that Hira has possible terrorist links and shuts her out of NorBAC. David must bring Hira back but he is confronted with a rally outside NorBAC, led by a fanatical reverend who claims that Christ can be cloned from a blood smear found on a nail from the True Cross at the site of the Crucifixion.

NorBAC investigates an outbreak of prion disease (mad cow) in humans. With the victims spread out across North America, how are the cases connected? In the aftermath of Hiras's death, David is determined to expose the fraudulent Reverend Walsh. David suspects that his old friend Danny, a hockey player, is using a dangerous performance-enhancing steroid.

As the search continues for the source of the deadly prions, NorBAC zeros in on a large agribusiness they suspect of selling infected chickens. David tries to convince Danny to stop gene therapy. Caroline insists that David interview Jill for the vacated virologist position at NorBAC. His reluctance turns to lust when he meets her.

NorBAC reviews an experimental treatment being tested on children with Leukemia. Just as they are about to declare the cancer therapy safe, another child dies. David disregards the proper channels and goes to Nunavut to get a sample of what he believes is the Spanish Flu virus from a frozen corpse. Mick and Lilith go whale-watching in Quebec and Lilith begins to realize just how sick he is.

Carlos Serrano, the Senior Researcher at NorBAC, wants to help a friend dying of AIDS participate in cutting edge research. He convinces David to help supply a Houston lab with contraband stem cells so his friend can be the first guinea pig for this radical gene therapy. When another child dies of Leukemia, David is determined to find out why the cancer treatment isn't working.

NorBAC discovers a plastic eating bacterium after a major power blackout on the Eastern Seaboard leads to fears of terrorist activity. David and Lilith's mother rekindle old animosities when she comes to town to help Lilith cope with Mick's death. Caroline is worried about the possibility of having breast cancer. NorBAC's Biochemist tells David he has been approached with another job offer.

NorBAC's bioinformatics researcher notifies the team of a case of privately contracted civilians returning from Iraq, exhibiting a wide range of mysterious illnesses. Carlos asks NorBAC to investigate multiple cases of hemophilia in a small community in Mexico, where a large multi-national laboratory is working on GMOs. When her research paper is refuted, Jill must defend her reputation.

In the investigation of the "Iraq War Syndrome," David suspects the water purification system has malfunctioned. Jill and Carlos' theory of a connection between a hybrid plant and the hemophilia epidemic in Mexico fails. David joins them and wonders if genetically modified mosquitoes could be responsible. Bob quits NorBAC to pursue his love of perfume creation. Caroline receives her diagnosis.

NorBAC is taken over by a joint command to deal with a catastrophic smallpox scenario. Bob tries to find a cure for his dog suffering from histiocytosis, Jill comes clean about taking medication for her panic attacks. David discovers the "Miranda Virus" outbreak may be linked to the U.S. government's secret bio-chemical lab and fears the manufacturer possesses another biological weapon.

A rampant SARS-like outbreak is occurring in Colorado and David is shocked when he discovers that the virus is the same Spanish Flu he dug up in Nunavut. Racked with guilt, he walks into the path of a car and is sent to hospital in a coma before he tells anybody his fears. Mayko heads to Colorado to try to find Patient Zero

Jill goes to Canada to see if the Spanish Flu body is still in the ground, while David recovers from his coma and returns to the office, where he identifies the vector for the Spanish Flu epidemic and tracks it with GPS. Daisy recognizes the person who infected her baby with the "Miranda Virus."