NCIS:LA uncovers a link to jewelry stolen from Iraqi museums when they investigate the murder of a Marine who was found in the parking lot with his hand chopped off. The victim, Corporal Thomas Porter, had Top Secret clearance and NCIS:LA must find out if any sensitive information has been stolen. Eric finds that Porter was under investigation while serving in Iraq after his commanding officer was found to be involved with trafficking stolen Iraqi artifacts out of the country. A parking stub found in the victim's car leads Sam and Callen to the store of jeweler, Jacob Rosen; when they arrive, Rosen is dead with his hand cut off. Rosen's phone records lead the team to an Iraqi-born jeweler, Aziz Ashiri, who they find was scheduled to meet Porter the day he was murdered. Kensi and Deeks find a bloody knife wrapped in what appears to be a ceremonial cloth in Aziz's home. Sam, knowing Aziz follows the laws of Sharia, sees the items were placed in a paper bag and knows Aziz was set up. The team re-examines the evidence and discovers a car that entered the parking structure right before Porter's murder was stolen from a fellow Marine by Porter's best friend, Corporal Petersen; Eric also finds that Petersen worked for Rosen as a courier. When Porter had jewels to sell, Petersen connected him with Rosen, but became jealous knowing Porter would get all the money; he killed Porter then Rosen in order to frame Ashiri for the crime and take the jewels for himself. Sam and Callen track down Petersen but he runs and chase ensues and it all ends in a shootout where Petersen is killed.