'NCIS: Los Angels' Season 5 LIVE STREAM ONLINE / Episode 6 "Big Brother" Preview / Callen Goes Back to High School [TRAILER]

NCIS: Los Angeles airs tonight with the Season 5 premiere of Episode 6 "Big Brother" at 9 PM ET on CBS. Apparently the West Coast agents are going back to high school to track down a 15-year old hacker.

One member of the team will go so far as to taking on the role of undercover substitute teacher.

In the trailer preview for tonight's episode, Kensi is in full teacher mode. High heels...check! Blazer...check! Everything seems to be right in line for a success undercover mission, except for her dark, dark memories of her days in high school.

She backs out and eventually team leader [Chris O'Donnell] takes the reigns of the operation.

But before you get too ahead of yourselves fans, NCIS: LA producer John Peter Kousakis already confirmed tonight's episode wouldn't have any more info on Callen's past. Fans got a huge dose of Callen's back story in the 100^th episode anniversary "Reznikov, N."

From now on the show will focus on the team leader's future, not what's already behind him.

Tune in tonight for NCIS: LA Season 5 Episode 6 "Big Brother" at 9 PM ET on CBS.

If you can't make it to a TV check out this live stream online:

http://www.couchtuner.eu/watch-ncis-los-angeles-online/

Here's a trailer preview for tonight's episode: