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.
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.