After Special Agent G. Callen (Chris O'Donnell) discovered the truth about his family in the previous episode of "NCIS: Los Angeles" season 7, his partner Special Agent Sam Hanna (LL Cool J) will learn that his own family will be subjected to a mysterious surveillance in the upcoming episode of CBS' action-packed police procedural series.

According to the spoilers for the episode titled "Revenge Deferred," Sam will have the most difficult task in his career while ensuring the safety of his family.

The synopsis for episode 17 reads:

"After extensive surveillance footage of Sam's family is found in Africa, Sam and Callen fly there to determine who is responsible and for what purpose. Also, Sam's family is moved from their home to a safe house."

In an interview with TV Fanatic in September 2015, series creator Shane Brennan revealed that Sam will encounter his hardest mission in the entire series in one of the episodes of "NCIS: Los Angeles" season 7.

"Sam will be confronted with his most difficult case, the most difficult situation he's ever been in as an agent or as a SEAL," Brennan said. "It has big repercussions. That's all I'm going to say."

The episode will see the return Jada Khaled (Ella Thomas) and her brother Tahir (Anslem Richardson) to the series. Fans of the show know that Jada used to have strong feelings for the NCIS special agent, but she was deeply hurt when she found out Sam used her to get insider information about her Islamic fundamentalist brother. Does it mean that Jada or Khaled has something to do with the illegal surveillance on Sam's family?

Meanwhile, Sam's partner Callen finally found out what his real name is in the previous episode of "NCIS: Los Angeles" season 7. In the heartwarming encounter between Callen and his long-lost father, the NCIS special agent learned that his real name is Grisha Aleksandrovich Nikoleav. They still have to spend more time together to make up for their lost time.

"NCIS: Los Angeles" season 7 episode 17 is slated to air on Monday, Feb. 29, on CBS.