The premiere, NCIS: Los Angeles Season 6 episode 1, picks up right where last season's finale left off. Sam and Callen are trapped on a submarine that's been converted into a bomb helmed by terrorists. With their air running short, Sam and Callen have to find a way out of the sub before it hits its target.

Meanwhile, their fellow agents search for information about the submarine and where it's going. Kensi finds a fertilizer receipt which leads them to uncover the true mission of the submarine. It was used to transport drugs, but now they find it's being used as a terrorist weapon.

The Navy searches for the submarine with plans to blow it up to prevent a much worse outcome. Will Sam and Callen make it out alive? Or will the sub blow up with them aboard?

Watch NCIS: Los Angeles online now to find out who makes it out alive!