On NCIS: Los Angeles Season 6 Episode 12, Callen's cover is blown right before a swarm of terrorists rig the building itself with explosives. Tom Blanchard attempts to negotiate with one of the men, and immediately gets shot in the foot.
They declare that they cannot be bought, and shoot Blanchard dead.
Deeks and Kensi train together and Kensi gets the upper-hand. News spreads of Callen's situation, and the team assembles. A plan to isolate Callen is integrated.
Granger, Nell and Beale brainstorm ways to disarm the explosives. Meanwhile, Deeks, Sam and Kensi gain ground on the remaining terrorists. One of the masked men reports two men down to his superior, and a group of the men are dispatched to sweep the area.
The leader of the group dawns a rigged vest, and a deadman's switch. He's willing to die for his cause, and take everyone with him.
Karen is almost executed by the terrorists, but Callen intervenes. He gets punched in the gut, and lined up alongside her.
Sam runs interference and they break up the terrorists. Sam cautions that the building is still rigged.
As Kensi and Deeks keep watch as part of the hostages, they plot to disarm the bomb attached to the explosive vest.
The first group looking for Sam, Callen, and Karen trip a wire and get blown away. The other group has a shootout with Sam and Callen in a stairwell.
Granger procures more information about the identity of the masked man.
Desperate for service, Deeks shoots down a huge glass window and dangles himself out in the sky.
The security guard and Kensi discuss the situation, while Sam and Callen hear the last words of one of the masked men.
Sam receives a static-y phone call from Beale.
Deeks hangs out the window and has a crucial conversation with Nell.
The security guard agrees to help Kensi and Deeks. They inform him they need about 90 seconds. He fakes an injury and the duo inch closer to the bomb.
Once he's within reach, Deeks, contemplates if it's yellow or black. He doesn't know which wire to choose.
He goes with his gut and yanks the yellow wire, saving them from a fiery death.
Hetty takes a firm stance with Granger, claiming that it's her team in the tower - and that she will make the phone call if she needs too.
Deeks disarms the bomb and sneaks back to Kensi. They regroup and charge at the masked man overlooking the security guard.
They tackle him as he shoots. They manage to knock him away just before he detonates the vest.
Sam claims that "spiral is secure."
However, Callen finds Karen and discovers that she was in on the entire scheme.
She nearly kills Callen in the process of fleeing the scene.
Deeks and Kensi take care of the wounded security guard, and receive a call from Sam as he heads towards the roof.
Karen greets him with bullets.
Callen get shot, and takes a tense trip to the hospital. When he finally comes to, him and Sam share an intimate moment. Sam sings a tune for a reluctant Callen.
At the end of the episode, Deeks and Kensi get interrupted by Nell and Beale, and they end up trying out "group zen."
Any prior sexual tension has now evaporated.