The Secretary of Defense puts NCIS on the case of Lt. Alex Quinn, a sailor dying of leukemia at Walter Reed Hospital. It is a top priority because the Quinn family has already lost two members in combat in the past nine months.

Alex needs a bone marrow transplant and the only family member left who could be a match is his brother Sean, who disappeared six months ago. Alex's life depends on NCIS finding Sean.

Gibbs meets with Alex's mother, who tells him that Sean spiraled out of control when her oldest son William was killed 9 months earlier. Sean began drinking, lost his job, and got in with a bad crowd.

Meanwhile, Bishop is home in Oklahoma, chopping wood. Her mother – played by "The Bionic Woman"star Lindsay Wagner -- tells her that she needs to face her problems, meaning Jake. The phone rings and we see Jake's photo in the display. Bishop chops the phone with the axe!

DiNozzo and McGee go to Sean's apartment. The manager says he is a great tenant. He pays his rent and doesn't throw parties. McGee finds a large stash of cash in an air vent, and several passports with Sean's photo but different names.

The money turns out to be counterfeit. DiNozzo and McGee tell Gibbs that Sean has been hitting casinos on the Eastern Seaboard, trading the fake money for the real thing. Gibbs tells them to loop in the Secret Service.

Special Agent Fornell shows up and says the FBI has been tracking a group of counterfeiters, including Sean, for the past year. Sean was recruited as a money washer by a friend from high school who ended up dead. So, Sean came to the FBI and is working as an informant. Sean can't get tested to see if he is a match, but Fornell offers to take Gibbs to him. When they get to the meeting point, Sean is missing, his FBI handler is dead -- and Sean may have shot him.

In Oklahoma, Bishop's brother George shows up after getting a call from their mom. He and Bishop have a talk about her relationship and she tells George that there isn't much hope for a happy ending. When George points out she is still wearing her ring, Bishop says marriage isn't something you just give up on.

They get interrupted by a call from DiNozzo, who feels they can't put all their eggs in one basket. He puts Bishop on the case of tracking down a potential donor. She finds the guy, former Army Sergeant Richard Doogan, but he is in Leavenworth prison serving life for for the murder of two Iraqi detainees in 2007.

Back at NCIS, Abby discovers that the bullet that killed the FBI agent also hit Sean, who needs medical attention.

Bishop goes to Leavenworth and meets with Doogan, who agrees to donate his bone marrow with one condition: He wants his life sentence reduced to time served, leaving him a free man.

Gibbs finds out from Sean's mother that Sean would probably go into hiding where he keeps his boat. DiNozzo and McGee find him unconscious, but still alive. DiNozzo reports back to Gibbs that Sean will survive but he isn't a viable match to donate for his brother. Doogan is the only hope.

Gibbs assigns DiNozzo to find out who shot Sean and killed the FBI agent. He has a plane to catch.

Abby and McGee search casino footage to find out who else is involved in the counterfeiting ring. The footage turns up Sean's landlord. DiNozzo and Fornell bring the landlord in and show him the gun. They have him on murder, so the landlord spills the beans on the counterfeiting operation to get a deal.

Gibbs show's up at Bishop's home and tells her the deal was approved. They head to Leavenworth, but Doogan isn't happy because the deal doesn't require his immediate release, only the possibility of parole. Doogan says if they want him to save Alex Quinn's life, they have to save his first.

Gibbs has dinner with Bishop's family. They are interrupted by a call from Jake. Bishop tells him she doesn't care where he spends Thanksgiving. George wants to tell Jake off, but Bishop tells him it is her problem to deal with.

Gibbs gets a call from McGee. Alex has taken a turn for the worse and they are running out of time.

Bishop tells Gibbs she wants everybody to stop treating her as if she is fragile. Gibbs asks her how many times she checked on him after he was shot. She says that is different because he almost died. Gibbs says her family just wants to make her feel better. She says she hasn't had time to process what Jake did. Gibbs says that she can't get better unless she talks about it. Gibbs reveals that he has been talking to Dr. Taft. He invokes Rule 28: If you need help, ask.

Bishop goes back to Leavenworth for one more try with Doogan. She says the deal is the only one he is going to get. She understands why he did what he did. He wanted revenge for the death of a friend. He isn't a bad person. He just did a bad thing. Doogan says he wants to make a fresh start. That's why he needs the deal. Bishop says he can make a fresh start by donating his marrow. Doogan agrees.

Back in D.C., Fornell, DiNozzo and McGee wrap up the counterfeit case. Fornell makes nice with DiNozzo and invites him home for Thanksgiving dinner. He says it is actually more of a punishment: dry turkey and burnt rolls.

Gibbs and Barbara have a heart-to-heart. She tells Gibbs it is nice to know her daughter has people who care about her. Gibbs promises to look after her. Bishop comes in and she tells Gibbs she is coming back. They peel potatoes together for Thanksgiving dinner.

New episodes of 'NCIS' return Dec. 15 on CBS.