NCIS: Los Angeles will hit another milestone in season 7.

'NCIS: LA' Season 7: New Director Announced, When Will Filming Begin?

It seems like just yesterday the NCIS: LA cast was celebrating it's 100th episode, but the series' 150th is now just around the corner. Set to air as the sixth installment of season 7, the landmark episode may hold a few surprises.

The CBS drama celebrated its last milestone by diving further into Callen's (Chris O'Donnell) past, and the series seems poised to unravel the agent's mysterious background even farther. Callen believes his father is dead, but dear old dad may actually be alive and kicking. After the events of "Chernoff, K.," viewers can expect new revelations to pop up faster than normal.

'NCIS: LA' Season 7: Writers Return To Work, EP Dishes Out Densi & Neric Teasers

"We ended [season 6] on Callen's father...or is it Callen's father?" Barrett Foa (Eric) teased at MCM London Comic Con, according to Red Carpet News TV. "There are some cool things I think are going to be revealed about our main guy who really has been searching for some answers to his family."

Could episode 6 play host to these reveals? Viewers can find out more when the cast returns to set later this week.

NCIS: LA airs Mondays at 10 p.m. ET on CBS. Click the video below to see a preview for the series' season 6 finale.

Tags: NCIS: LA NCIS: Los Angeles television CBS