NCIS: LA: Is a New Big Bad About to Emerge?

Sunday's episode of NCIS: LA found Callen (Chris O'Donnell) on a mission -- to fully rebound from Joelle's betrayal.

Things are heating up between Callen and Anna (Bar Paley), literally, as they enjoy a romantic evening in front of the fireplace. Unfortunately, just as things are starting to get beyond PG-13 territory, they're interrupted by Hetty (Linda Hunt), who shows up on Callen's doorstep to give him and Anna an assignment: They're going to Arizona in order to retrieve terrorist Ahmed Han Asakeem (Sammy Sheik) from prison and escort him to Los Angeles for his deposition.

Asakeem, as a refresher, is the terrorist who the team went after in Syria way back in the beginning of the season, and who was riding with them in the helicopter that crashed and left Kensi (Daniela Ruah) in a coma.

NCIS: LA: How did Granger say his final goodbye?

After hearing that news of Asakeem's transport has sparked "chatter" on terrorist channels, Callen and Anna opt to take the scenic route in order to avoid commercial flights and major highways. During their "road trip," even Asakeem can't help but gag at their flirtation, as they loudly belt "You're the One That I Want" and other duets in the car.

But they run into trouble upon stopping for a bathroom break, where some rednecks in a diner immediately take some verbal jabs at Asakeem -- who responds to them by provoking them further, making comments about American soldiers he's killed. Luckily, Callen and the local sheriff are able to put a stop to the near-skirmish, but as they're getting back into the car in the parking lot, they're ambushed by men in black jumpsuits who open fire on them. With a little help from the diner patrons, Callen and Anna fatally shoot the men, but the question is, who are they? And who are they working for?

Elsewhere, Sam (LL Cool J) goes undercover to bring down a notorious drug lord known only as "The King" -- and who, it turns out, is actually a woman. She's killed in a shootout after Sam leads Deeks (Eric Christian Olsen) & Co. straight to her -- but that case ends up having a twist as well. The King's distributor is actually the LA district attorney, who's been publicly championing the war on drugs while, all along, personally funding it.

Once Asakeem has arrived safely in Los Angeles, Anna and Callen celebrate a hard day's work by making out on a couch back at headquarters. But it's likely they're going to get interrupted again before they can take things too much further. Beale (Barrett Foa) traces the sat phones found on their mystery attackers to a cabin near the prison where Asakeem was being held, that has recently been blown up. He discovers that whoever was in the cabin was tracking several prison facilities and so, for whatever reason, clearly has a vested interest in monitoring Asakeem's whereabouts. Is there a larger threat at work?

NCIS: LA airs Sundays at 8/7c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)