Infestation (Harbingers): Episode 6

Unleashed from caves used for occult rituals, a microscopic evil invades the world--an infestation that deceives, blinds, kills, and then spreads and kills again. Is it natural, supernatural, or both? An embittered Professor McKinney must rejoin the Harbingers team in order to discover the truth and confront a monster bent on destroying humankind.