History and Use
Keller claimed that she had originally developed the pathogen to free programs; its use by Tesler was one of the factors which incited her to leave Argon City. The pathogen, taking the form of a reddish haze, was first dispersed by tankers programmed to crash on the highway, allowing the haze to escape and infect programs involved in the resulting traffic pileup. Later, the haze was released during a concert in Argon Square as part of an attempt by Tesler to brainwash the citizens of Argon City en masse.
The pathogenic code infected programs who breathed it, allowing the brainwashing effects to be activated by signals from a tall tower. Infected programs could be distinguished by their behavior -- immediately professing devotion to Clu and violently opposing any treason against the Occupation -- and by their eyes, which took on a red glaze.
When the signal tower was destroyed, the pathogen lost its effects, and Tesler's people were unable to recreate it.