While in New York, David has his bag stolen. Chasing the kid who stole it, he finds himself in some subway tunnels where he discovers a young girl who is very sick.

Jill's new treatment for juvenile diabetes is halted when she discovers than the stem cells hold a retrovirus that might endanger the patients. The research on what plagues the girl found in the subway tunnel continues.

David and Carlos are still investigating the poison that is affecting Charringa's lemon crops in Florida, before the United States decide to bomb Cuba. Jill, on the other hand, asks Mayko to contact all the other labs using the same stem cells from Korea to let them know a retrovirus is in that strain. Bob offers to verify all the steps one more time with her and see if her findings are correct. Simon Jessup finding that Glenn responds to all the stimuli suggests that he undergoes brain surgery.

Bob is trying to prevent a rain of concentrated sulfuric acid that would destroy Mexico City. Homeland Security suspects two American scientists of preparing a bio-terrorist attack against the United States President and order David and Caroline to investigate.

There is a series of suicides in Arkansas that Norbac is called to investigate. David tries to decipher the work of a friend who died in a car accident.

As the investigation continues on the suicides in Arkansas, the team believes it is a chemical release by worms that is the cause. Owen is charged with criminal negligence for the death by overdose of a school girl.

What happened to Bob, Mayko, David, Jill and Caroline? 6 months after the explosion, NorBac is still rebuilding itself. The team has to deal with the deaths of several of their friends and colleagues and the arrivals of new people for the team.

NorBac must find a cure to a bacterium that will surely kill David and Bob if they do not succeed. They also need to engineer the cure so that it eradicates the bacterium that was probably transported by the wind after the explosion of the lab in Utah.

The US government wants to cut over $3 billion out of the science budget, and NORBAC has to prove they deserve to stay in operation. Meanwhile, a West Nile like virus is breaking out in San Francisco, but it's showing some abnormal traits. A scientist at the University of Toronto claims to be able to help Owen with his addiction.

Mayko finds the missing link to the Sinatra syndrome; Owen tries to commit suicide.

The team traces the Sinatra virus to an organ donor in the Philippines; David blames himself for allowing Owen to try experimental gene therapy to cure his drug addiction.