NCIS: LA investigates the murder of Dean Albee, a member of the domestic terrorist organization called the Gun Barrel Party (GBP) who has been in hiding for the last forty years. Albee was killed deep in the Angeles National Forest by a knife wound to the chest, but after a sweep of the area and his forest dwelling, the team hits a dead end. They dig into GBP's history and discover that the only other living GBP member is spending life in prison, so they look at his recent visitors, and that points them in the direction of Dr. Dennis Hale, a history professor at a local college. Initially, it appears that a local student anarchist group could be behind the resurgence of the GBP, but after a bomb destroys Hale's house and another is found on campus, the team discovers that Hale is actually one of the original members of the GBP. He faked his own death twice in an attempt to evade arrest and continue spreading his anti-government message. After Hale's arrest, his class TA, David Thompson, tries to convey the message on his own with a shooting spree on campus, but Kensi is able to talk him down before any shots are fired.