Battlestar Galactica Episode 1.06 Litmus

When a new copy of Doral, a Cylon who had been previously exposed while serving as the Galactica's public-relations officer, sneaks aboard and blows himself up, killing three people, Commander Adama and President Roslin must finally make public the terrifying secret known only to a select few: Cylons now look like humans.

Adama also appoints an independent tribunal to investigate the recent security breaches and names Sgt. Hadrian as lead investigator. When Hadrian discovers a hatch was left open, even after Chief Tyrol had reported that all were closed, she focuses the investigation on him and his relationship with Sharon.

Tyrol's crew covers for their chief, taking the blame for his failure. When Hadrian tries to expand the inquiry, haranguing Adama about his decision not to reveal the truth about Cylons, the commander shuts down the tribunal.

Meanwhile, on Caprica, a trio of Cylons observe Helo as he tries to save himself and find the woman he thinks is Sharon.