At an ATM on a public sidewalk in Westwood, California, in the burbs of Los Angeles, a man dies of a detonation of an explosive device planted in his cellphone; the victim, Ross, previously served as a staff sergeant in Iraq with a Marine explosive-ordnance-disposal (EOD) unit; the Callen team investigate. When Sam visits King, one of Ross's fellow EOD Marines, King has just discovered a bomb under his truck; while G and Kensi watch, Olin, another fellow EOD Marine, sustains injuries in an explosion of his car, on which someone has written in Arabic on the rear window; the team research Tariq, yet another fellow EOD Marine and a Muslim, born and raised in Michigan, then Kensi flushes him out, and Nate chats him up. The team reach an agreement on the identity of the bomber; Kensi, G, and Sam meet one of the fellow Marines at his workplace, where they also meet, collar, and cuff the bad guy. Afterward Nate does a good Christmas deed.
—DocRushing