David and Bob investigate simultaneous explosions that incinerated a high tech lab and several of its employees; new virologist Rachel Woods studies the DNA of a gay-basher suspected of killing a fellow student.

David and Bob become ticking time bombs after ingesting the same deadly bacteria combination that incinerated the Greenway scientists; an anomaly in the genetic makeup of gay-basher Julie Henshaw temporarily puts Rachel off track.

A West Nile-like virus is breaking out in San Francisco, but it's showing some abnormal traits. NorBAC faces budget cuts on the U.S. side; a scientist at the University of Toronto claims to be able to help Owen with his addiction.

Outbreaks of a deadly virus in San Francisco and Boston have NorBAC scrambling to find a Patient Zero; Owen wastes away in a jail as David and Angelica argue over his treatment options.

NorBAC traces the Sinatra virus to an organ donor in the Philippines; massive mercury contamination in Washington State's pristine wilderness leads the team to suspect an underlying cover-up in the government.

NorBAC continues to investigate outbursts in San Fransisco, Boston and Tampa, but stumbles upon a possible mercury poisoning in Washington state.

The team tracks a deadly strain of C.difficile.

Bio terrorism is suspected as forest fires fuel the spread of deadly toxins.

A weaponized biological agent was released during fires on the west coast, NORBAC must find the creator of the agent. However, Rachel is more worried about her son who was attacked by a bear.

A chef is stricken with the same delirium that caused a bear to attack Rachel's son.

A strange insect bites Carlos as he conducts research.

Magnetobacteria jeopardizes the country's electronic infrastructure.

A link is found between the smallpox scam and the tantalum contamination.