Alias Season 3 Episode 18 : Unveiled

Sydney and Jack warn a disbelieving Vaughn about their suspicions of Lauren being the CIA mole. Meanwhile, Bomani and Sark take possession of the Rambaldi machine, Sydney and Vaughn must stop a Covenant virus that's crippling medical facilities around the world, Sloane's secret is revealed to Jack, and Bomani begins to lose faith in Lauren's ability to carry out her Covenant missions.