"NCIS" Season 11, Episode 12, "Kill Chain," is the second half premiere of the crime series. McGee's girlfriend Delilah got injured in an explosion. Her life hangs in the balance, as terrorist Parsa slips away. Meanwhile, many fans were happy to see Susanna Thompson as retired Col. Hollis Mann again.

Spoiler alert: This feature contains major spoilers on NCIS 11x12, aka Kill Chain. Fans might want to know that NCIS showrunner Gary Glasberg has described the Season 11 winter episodes to be a roller coaster ride with Benham Parsa.

Ziva David (Cote de Pablo) is still somewhat present, thanks to a tiny flag at Abby's lab. But it's now time for Ellie Bishop to shine. NCIS Season 11x12 proof? She just got a picture-worthy parking space at the Navy Yard. Another proof: Gibbs (Mark Harmon) trusts her to find Benham Parsa.

Col. Hollis Mann is now with DOD, and she insists to work with Gibbs' team again. Tony (Michael Weatherly) shows Ellie Bishop a presentation of Gibbs' ex-wives. Leon Vance (Rocky Carroll) senses the odd energy upon the former colonel's arrival.

"She's not another one of your ex-wives, is she?" Leon asks. Gibbs smiles meaningfully, and responds, "Close enough." Mann later tells Gibbs' she's married, and she's sorry for having left him six years ago.

NCIS 11x12: The Case of the Week, Case of the Mid-Season

NCIS Season 11, Episode 12 opens to a sailor, Petty Officer First Class Daniel Coyne, being shot dead by a stolen drone. NCIS links the crime to terrorist Benham Parsa. He is currently in the U.S. and his "Brotherhood of Doubt" is anticipated to launch more attacks.

Delilah Fielding (Margo Harshman) is being recognized for her work against counter-terrorism. Apparently, she's no small name at the Department of Defense. Even Ellie Bishop is a fan of her work.

Delilah wants to take Tim McGee to the awards gala, which gathers the biggest names in the field of U.S. intelligence. McGee clearly doesn't want to go. It turns out Delilah has already taken care of it. She's got a tuxedo custom-made for McGee even before she asked him to the awards night. (She tells him she knows her boyfriend's inseams.)

In her lab, Abby tells McGee she thought he likes Delilah. He responds, "I did," and immediately corrects himself, saying, "I do." Abby then convinces McGee to go to the awards gala, saying Delilah is the best thing that's ever happened to him. Throughout this scene, a small Israeli flag in front of Abby and McGee is sparking memories of Ziva David (Cote de Pablo) among many viewers.

After piecing together all the information they've got, Gibbs' team realizes Parsa is bombing the awards gala venue. The explosion occurs while McGee is outside, taking Tony's warning. Mann and Gibbs are on the road to arrest Parsa. Delilah suffered critical shrapnel wounds.

Gibbs almost catches Benham Parsa (Karan Oberoi), but his men have solid contingency plans.

Toward the end of NCIS 11x12, Mann tells Gibbs he'd catch Parsa. (Based on fans' reactions on Twitter, Mann is likely to return for more NCIS episodes despite her busy schedule doing "Arrow" on The CW.)

What happens in NCIS Season 11, Episode 13?

"A bomb goes off. A loved one goes down," says the NCIS Season 11, Episode 13 promo. This episode is called, "Double Back."

"His judgment could be impaired," says Dr. Rachel Cranston in the sneak preview. Viewers think she is referring to McGee, shaken by what happened to Delilah. The elder sister of the late Caitlin Todd is going to help Gibbs' team heal in the midst of the Parsa crisis.

Read More TV Guide Features and Spoilers

'NCIS' Season 11, Episode 12, 'Kill Chain' Spoilers; Emily Wickersham Talks About Cote de Pablo, Ziva David Returning for Finale? [READ]
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Watch NCIS Season 11, Episode 13 Promo Clip: 'Double Back' (CBS on YouTube)

NCIS Season 11, Episode 13, 'Double Back' airs on Jan. 14 on the CBS. Does McGee lose Delilah, or does this Parsa crisis bring them closer than ever?