
After the events on 9/11, a team of experts track down the killer and mailer of the anthrax letters.

Episode 1
In Florida, a man mysteriously falls ill and dies. Special Agent Matthew Ryker suspects an anthrax attack - how many others have been infected?

Episode 2
Ryker’s investigation moves to New York as another case of anthrax occurs. Bruce Ivins begins having suspicions of his coworkers.

Episode 3
An attack on Capitol Hill sends Ryker and his team to a mail facility that’s become a hot spot for anthrax infections.

Episode 4
The FBI learns more about Bruce Ivins’ peculiar past behaviors after an old colleague raises red flags. Ryker and Dani trace the origin of the letters.

Episode 5
All eyes shift to “Mr. Z.” As they start to zero in on a suspect, Ryker and Dani get new assignments - but that won’t stop them from chasing their lead.

Episode 6
With two suspects in question, Ryker’s own beliefs about the case are tested.