FX: The Series - Season 2 Episode 13 Reaper

Random deaths in Kansas...the cold-blooded murder of a militia cell in Pennsylvania...the apparent suicide of a government scientist in New York -- threads that lead Rollie and Mira into a shadowy world where nothing is as it seems. When they learn the conspirators intend to wipe out the only people who know the truth about a bio-engineering project gone horribly wrong, Rollie faces the ride of his life, dangling from a helicopter riding a nerve gas weapon, in a race against certain death -- for himself and half of New York City!