NCIS: Los Angeles airs a new episode tomorrow night, after NCIS as always.

In "Patriot Acts," a former Marine is suspected of creating a chemical weapon, prompting the special ops team to join the FBI’s domestic terrorist task force - including a face familiar to fans since the first season.

Operational Psychologist Nate Getz (Peter Cambor) makes another return to the series this week. Check out the promo below and click to enlarge some photos from the episode as well ...