Purity is the twentieth episode, in the fourth season of NCIS: Los Angeles, and the ninety-second in the series as a whole excluding the back door pilot episodes and any crossovers.


When cyanide in a communal water jug lethally poisons a lieutenant and leaves a Navy pilot in serious condition, the NCIS: LA team investigates whether this is an isolated incident or an early test for large-scale water contamination as the search for the source of the cyanide.


Series RegularsEdit

Actor/Actress Character Role
Chris O'Donnell G. Callen Special Agent in Charge
LL Cool J Sam Hanna Senior Special Agent
Linda Hunt Henrietta Lange Operations Manager
Daniela Ruah Kensi Blye Junior Special Agent
Barrett Foa Eric Beale Tech Operator
Eric Christian Olsen Marty Deeks LAPD Liaison
Renée Felice Smith Nell Jones Intelligence Analyst, NCIS: OSP

Recurring CastEdit

Actor/Actress Character Role
Kent Schocknek ZNN Reporter Schocknek previously played a reporter for ZNN in Dead Body Politic and Paper Soldiers

Other CastEdit

Actor/Actress Character Role
Tom Gallop Lawrence De Vries
Chris Bruno Dominic Fryman
Jay Ellis Flight Officer Randall Baker United States Navy
Omar Elba Zaki Faheem
Owen Teague Alex Fryman
Steven W. Bailey Cam
Mark Espinoza Detective Lopez Los Angeles Police Department
Lily Mariye Ashley Hong
Travis Aaron Wade Chief Petty Officer Crawford United States Navy
Steve Tom Roger Steve Tom also played Morgan
Rance Howard Eugene
Jade Carter Lieutenant Joshua Gordon United States Navy
Bree Condon Alessandra

Production NotesEdit

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.