: The episode features interesting trivia about "Prussian blue," a pigment used as an indicator in cyanide tests and a treatment for radiation poisoning.
The investigation begins when a Navy lieutenant is lethally poisoned by cyanide in a communal water jug. The team quickly discovers this was merely a trial run for a much larger attack by a radical protest group known as "Designing a New America" (DNA). Their goal—allocating the defense budget to education—is noble on the surface, but their method is murderous. Standout Moments & Character Dynamics NCIS.Los.Angeles.S04E20.HDTV.x264-LOL.[VTV].mp4
: G. Callen (Chris O'Donnell) infiltrates the group by staging a public brawl with Sam Hanna (LL Cool J). This leads to a tense sequence where Callen's cover is blown, and he is nearly killed by the very cyanide he's investigating, only saved by a timely counteragent. : The episode features interesting trivia about "Prussian
Review: NCIS: Los Angeles Season 4, Episode 20 – "Purity" "Purity" is a high-stakes, technically intriguing episode of NCIS: Los Angeles that leans heavily into the team’s undercover capabilities. Originally aired on April 9, 2013, the episode centers on a domestic terrorism plot involving cyanide poisoning. This leads to a tense sequence where Callen's