: The extremists aim to blend into the city and use the water system to poison the government facility.

Hondo and his team join forces with the FBI for a massive manhunt to locate a militia group known as the "". The group plans to execute a domestic terror attack by weaponizing cyanide , targeting a state agency's headquarters by pumping the toxin into the local freshwater system.

: The team conducts a high-risk raid on an extremist compound and a subsequent operation at the Venice Marina to break up a cyanide sale. Character & Subplot Development Contamination | S.W.A.T. Wiki | Fandom