NCIS: Los Angeles - Season 2 Episode 3 -

On state-owned property near Imperial Beach, California, south of San Diego, while four Marines patrol the area (along the US-Mexico border) to support federal customs and immigration agents, unknown people for unknown reasons ambush the Marines and their Humvee; one escapes, and three remain missing; officials wonder whether the intruders are Mexican smugglers; Callen and company investigate. A search party finds the body of one Marine; the lone survivor says that one of the missing is a pregnant lance corporal, and the dead one was the father; a snitch gives a tip ...