: The investigation begins when a Navy lieutenant and a civilian die of cyanide poisoning after drinking water from the same communal jug at a bikini bar.
: The team discovers the incident was a "trial run" by a radical protest group called "Designing a New America" (DNA). The group plans to release cyanide into the city's water supply to make a political statement.
: Indicates the file was distributed or indexed by the ETTV community. Cast & Credits G. Callen Chris O'Donnell Sam Hanna Kensi Blye Daniela Ruah Marty Deeks Eric Christian Olsen Hetty Lange Linda Hunt Director Eric Laneuville Writer NCIS: Los Angeles Season 4 Episode 20 Recap: Purity
In this episode, the OSP (Office of Special Projects) team investigates a potentially catastrophic chemical threat in Los Angeles.
: Encoded using the H.264/MPEG-4 AVC compression standard.
: Callen goes undercover by attending a DNA rally, where he stages a fight with Sam to gain the group's trust.
: The "release group" name, a well-known entity in the TV scene.
: Callen’s cover is blown, and he is nearly killed by cyanide himself, only surviving by using a counteragent. The team eventually locates the group's base and prevents the mass poisoning. Technical File Details