Although executive producer Brian Peterson said he and executive producer Kelly Souders probably had “about 100 ideas” for a second season of “The Hot Zone,” diving into the anthrax scare that followed in the wake of the Sept. 11, 2001 terrorist attacks quickly rose to the top for them.

“The first season was very much about an outbreak. It was about a virus,” Peterson explained during the show’s Television Critics Assn. press tour panel on Aug. 18. “This is a story that’s about bacteria and about a very targeted situation that still lived within the same timeframe and world, roughly, as the first season, so it felt like a really good companion piece.”

The first season centered on the ebola crisis in the early 1990s while the second follows both FBI Agent Matthew Ryker (Daniel Dae Kim) as he investigates the suspicious mailings sent to newsmakers and government officials and fights to...