The investigation of a drive-by shooting has the NCIS team searching Los Angeles for the dead marine's younger brother who may be the next target and the one with the answers.
After a sailor is killed during an underground street race, the NCIS team determines that his car had been sabotaged and contained confidential Navy equipment. Meanwhile, Callen is forced to take traffic school.
The death of a lieutenant commander appears to be suicide but the NCIS team uncovers evidence corresponding to murder. Also, Operational Psychologist Nate Getz joins Special Agent Kensi Blye in the field.
While Hetty is attending a Senate hearing in D.C., the investigation of a murdered Marine Lance Corporal leads the NCIS team to stolen anti-tank missiles and a dangerous militia group.