NCIS: Los Angeles will take another look at Callen's mysterious past in episode 20.

'NCIS: LA' Season 6 Spoilers: When Will Nate Getz Return? Peter Cambor Hints At Future Role 

Information regarding Callen's (Chris O'Donnell) family tends to come in spurts, but the CBS drama hasn't addressed the agent's personal history in quite some time. It looks like this will change in "Rage."

Written and directed by Frank Military ("SEAL Hunter," "Black Budget"), episode 20 (filming as 618) will reintroduce viewers to a young Callen.

'NCIS: LA' Season 6 Spoilers: Why Does The Cast Have Marionettes [PHOTO]? Nell Enters The Field In New VIDEO For 'Blaze Of Glory

"Great prep this week [for "Rage"]," executive producer John Peter Kousakis tweeted on Friday. "[Frank Military] is at the helm. Great story. Callen, young & old, major interest & focus."

The last time viewers received information regarding Callen's history, it came in a deluge. NCIS: LA's 100th episode, "Reznikov, N.," introduced the man who had been keeping tabs on Callen and his sister all these years. While this new man wasn't related to Callen, he did know the orphan's father, and provided Callen with his first look at the man himself.

Will "Rage" provide more answers to the puzzle? Find out more when NCIS: LA airs Mondays at 10 p.m. ET on CBS. The airdate for "Rage" is currently unknown.

Click the video below to see a preview for the series' latest episode, "Expiration Date."