NCIS: Los Angeles Special Operations team will take on some big storylines as the series reaches its "zenith" in season 6.

NCIS: LA Season 6 Filming Start Date Set, More Directors Announced

The CBS drama left fans worrying about Callen & Sam's safety, Hetty's job, and Deek's and Kensi's relationship at the close of season 5, and the series will not slow down as it moves to a new night and time this fall.

"#NCISLA will reach its zenith in S6. NEW NIGHT...MONDAYS @10pm," teased executive producer John Peter Kousakis in May. "Stories will be better than ever. #staytuned #willnotdisappoint #BringItOn"

Kensi & Talia To Fight Over Deeks In 'NCIS: LA' Season 6 Premiere, Trouble Brewing For Densi?

Now that preproduction has started for the season's second episode (the premiere was filmed directly after season 5's finale), NCIS: LA's writers are singing the same tune.

"This gonna be a BIG season," tweeted writer Kyle Harimoto ("Three Hearts," "Merry Evasion") on Monday. "Hope you guys dig. #NCISLA."

When Hetty's team does finally return from their summer hiatus, Callen and Sam will quickly find themselves in even more danger as their bomb-laden sub starts to take on quite a bit of water. Meanwhile, Kensi and Deeks will take to the skies to track down the missing agents while dealing with Talia's flirtatious advances.

Find out more when NCIS: LA returns on Sept. 29. Click the video below to see a preview of the series' latest episode, "Deep Trouble."