On the season five finale of "NCIS: Los Angeles," the team investigated the suspicious suicide of a government worker, which ends up being tied to a dangerous terrorism case.

In "Deep Trouble," a gang called the "Brotherhood" is being investigated when a body falls off a bridge while they're also on the bridge. The victim was Lt. Commander Steven Hill, an engineer officer who worked on nuclear submarines.

His autopsy report shows that there was a large amount of cocaine in his system as well as evidence of needle use, which indicates a drug overdose. However, the team learns that he died before he fell off the bridge, meaning someone could have set it up to appear like he committed suicide.

A kid was filming the gang when Hill died, so he hands his tapes over to NCIS. Eric (Barrett Foa) is able to track down the type of car heard in the background of the video due to the engine's acoustic sound. It leads them to a man named Michael Wilson.

But when the team gets to his house, people start shooting at them, and a grenade is thrown in their direction. Sam (LL Cool J) throws it back, blowing up the suspects. They then go into the house and find a woman shackled to the bed who had been shot in the face.

Talia, who is investigating the gang, tells the team that they were already under investigation because they are some of the biggest meth dealers on the West Coast. She also says they're forming new drug alliances.

It turns out the woman who was shot in the face was the wife of a man who owns a yacht-building company. Sam and Callen (Chris O'Donnell) question the businessman, and he says that the drug dealers wanted him to design and build a submarine, which he agreed to give as ransom for his kidnapped wife.

A GPS system leads the team to the sub. Callen finds ammonium nitrate inside. Someone then begins shooting at him, so Sam comes aboard to help defend him. Three men who appear to be terrorists board the submarine and lock them in a room on the sub.

Meanwhile, back at the headquarters, Hetty (Linda Hunt) leaves for Washington, D.C. to answer to a committee about her actions in the White Ghost situation. She leaves Nell (Renee Felice Smith) some instructions, signaling that she may not be returning for awhile.

Also, Talia and Kensi (Daniela Ruah) have a bit of a flirting contest to vie for Deeks' (Eric Christian Olsen) affection, with Kensi clearly threatened by Talia.

But at one point, Talia calls Deeks out on being "madly in love" with Kensi, and although Deeks tries to deny it, it's clear that their love for each other is obvious.

The episode brings season five to a close with Sam and Callen trapped on the sub, in danger of being blown to bits by terrorists. Will the team save Sam and Callen in the nick of time?

Fans will have to wait until September to find out.

What did you think of the cliffhanger season five finale? Leave your thoughts in the comments below.