In the final episode the race is on to find out who is going to release the flu. The gang track down Dobri Gorski to a police cell, where he tells them the names of the three people he trained to release the flu. A process of elimination leaves them with Terrence, but they still have to find him. Wilson's new ruthlessness is unnerving - can he be trusted? And what will happen when Becky runs out of Thoraxin?