The squad will be tapped to investigate a possible radiation poisoning of a gunnery sergeant in the upcoming episode of the long-running CBS series "NCIS: Los Angeles."

In "Core Values," CarterMatt reports that an undercover official is found poisoned with what looks like toxins from a nuclear power plant. The gunnery sergeant is posing as a security guard for the place when he gets debilitated. To find out if the owners of the plant have been remised of their duties to ensure safety of their people, NCIS will send in Deeks (Eric Christian Olsen) and Kensi (Daniela Ruah) to work on the case.

The pair will go clandestine in this investigation. This will also be the first case they will be working on after Deeks' unfortunate run-in with the authorities. During the midseason finale, he was questioned for the murder of his former partner. It was determined that Deeks indeed killed the guy in defense of someone important to him. The fact that he did not readily admit the truth to Kensi put a wedge between them, but they were able to work things out in the end.

Last episode, the team investigated a man who got run over by a truck transporting Christmas trees. It was soon realized that the victim was not an ordinary citizen, but a suspected North Korean spy. He also had a lot of toxins in his system, which explained why he was inebriated as he weaved through the oncoming traffic. They traced his cover to a furniture store, where another mole was hiding. It turned out she was the one who drugged him.

The NCIS next probed to find out how the spies got into the country. They apprehended a smuggler, who just got out of jail. He agreed to help them with the sting operations to capture the bigger fish. In the end, the team was able to close down the operation and celebrated Christmas with their families.

"NCIS: Los Angeles" season 7 will return on Monday, Jan. 4, 2016, at 10 p.m. EST on CBS.