Last night on a special NCIS, Ducky’s past is brought to light once more as we find out information about his family. The episode opened with Ducky in autopsy when he gets a call on his phone. Someone is calling with information about a relative and he is shaken as he leaves. Jimmy is coming in when he sees Ducky leave and is confused to see that a mess has been left on the floor.
Meanwhile in the bullpen, Tim and Tony are observing Ellie, who has returned from Oklahoma. They are trying to figure out if she is still married or not. Ellie tells them she can hear them despite their whispering and her hint allows Tony to realize how Gibbs always hears them before they notice him. Of course, Gibbs shows up to let them know they have a case.
Their victim is Marine Private John Angel, who appears to have been beaten. Jimmy arrives without Ducky, much to Gibbs’ confusion. When asked where he is, Jimmy admits he hasn’t seen him since he left and that he hasn’t returned Jimmy’s calls. Gibbs tells him to call again and when he does, they hear Ducky’s ring tone. They go over to a blue van and open it to find Ducky tied up.
Ducky tells Gibbs that a man called him and was fishing for information on a relative. He tried to leave when he realized what was happening and was followed. When they show him the victim’s body, he tells them he wasn’t the attacker, but he was in the coffee shop where he met the caller. He admits to Gibbs the man was asking about a brother named Nicholas. Gibbs has never heard of him and is surprised. Ducky tells him Nicholas died years before they ever met and doesn’t know why anyone would ask about him.
In a flashback, we see a young Ducky seeing his little brother, Nicholas. His stepmother is not the best mother in the world and leaves on Christmas Eve so Ducky spends it with his beloved little brother. He gives him a train set and claims a relative made it, but Nicholas has his number. But before they can enjoy the night, Ducky gets a call to rush back to the hospital, so he takes Nicholas with him.
In the bullpen, the team talks about John Angel and Tony says witnesses saw John run out of the coffee shop when he heard Ducky yelling. It was likely that he had been trying to save Ducky. There is no information on the caller, but the van did come back to Sam Butler, a man who often used a service to rent out his vehicle. Ellie comes in with a sketch from Ducky’s memory and is surprised when Gibbs tells her Jake called and is on his way to the office.
When Ellie mentions Ducky’s brother, he has another flashback to when he took Nicholas to the hospital. A patient is in pain and requested Ducky since he heard other soldiers talking about how good he was. Ducky is able to figure out he needs surgery right away and prepares. But before he can perform surgery, his father arrives and tells him his stepmother is divorcing him and plans on taking Nicholas.
Tim and Tony go to talk to Sam Butler, who had rented the van to Rufus Simms. He isn’t the man in the sketch, but a friend he was with matched the description. Rufus is renting Butler’s house while he spends the night in a tent with a girl. The girl walks out and as they are about to go in to talk to Simms, she cries out. They rush over and see through the window that Rufus is hanging from a rope.
Ducky has Rufus in autopsy and has determined that he didn’t commit suicide. He has water in his lungs consistent with the swimming pool found in the back of the house. Ducky doesn’t recognize him and doesn’t know why he’d be asking about Nicholas. Ellie comes in and tells him that a letter for Ducky was in his suitcase. The letter is written on old stationary and looks like Nicholas’ handwriting. He tells Ducky in the letter he misses him and that he owes him a hot chocolate.
In a flashback, Ducky is in a car with Nicholas on his way to a pub. He mentions that Nicholas’ hot chocolate looks cold and he needs to get him a new one. While Nicholas plays a game, Ducky talks to Angus Clarke, his old friend who is with the woman Ducky was in love with. He needs Angus’ help with custody of his brother. His stepmother wants 10,000 pounds in exchange for Nicholas. Angus agrees to help.
The present shows Ducky has no idea why Rufus had the letter. Before they can continue, Jake arrives to talk to Ellie. They go into the garage, where McGee is processing the van. He carefully hides while overhearing the couple talk. Jake wants to work things out, but Ellie is no longer interested in being with him.
In the lab, Abby is playing a game where she is smacking Jake’s face when Gibbs walks in. She tells him that she was able to use lab work to determine the last thing Rufus googled on his computer. He had been looking for a pawnshop. Before he leaves, she gets new results on the letter that Ellie gave Ducky. She is shocked to discover that the letter was written three weeks ago. If Nicholas wrote it, then he is alive.
Gibbs and Tim tell Ducky about the letter, but he is shocked since he always thought his brother had died. The handwriting resembles that of a child, but his brother could now be in his 50’s. Tim tells him they are going to go to the pawnshop to see what is going on.
Tim and Tony go to the pawnshop, where the owners are filming a YouTube video. They ask questions, making sure not to be on camera, and find out that Rufus came in with a friend, who resembles the sketch, to pawn rare stamps. They only had one stamp that came with a companion and the two men got into a fight over how much the stamp was worth.
They were able to get surveillance and Ducky identified his attacker. It is a private investigator named Viggo Trellis, who Rufus had hired. Ellie is having trouble concentrating, but then bucks up and is able to tell them information on Rufus, including that he likely got the letter to Ducky from the post office. He had hired Viggo to find out who had the stamps.
A flashback shows Ducky checking on his patient, who is doing better. He also has Nicholas’ stamp book, which had been left behind, and he had filled it with his own collection. Ducky leaves with Angus, who tells his old friend that he will give him the money for Nicholas. But just as they celebrate the good news, Ducky gets a call that his stepmother is trying to leave with Nicholas.
Ellie isn’t able to use GPS on Viggo’s phone, but she hacks into the microphone. She hears him driving with a man he calls Nicholas. Ducky is distressed thinking it is his brother. They listen for clues on the phone and when Tim hears wind chimes, Tony realizes they went back to the crime scene. Ducky wants to go with the team.
A flashback shows Ducky with Nicholas telling him that he won’t lose him. But his brother is prepared to leave and has informed the police so they can prevent Ducky from taking Nicholas. As Nicholas struggles from her grasp, he drops the train his brother gave him.
At the crime scene, Ducky hears a gunshot and rushes inside. Viggo has been shot, but when he sees his hostage, he realizes it is not the right Nicholas. He mournfully makes a call to Jimmy.
The final flashback shows Ducky by himself as Angus comes in. They believe his stepmother went to Albania to be with family. Ducky informs him that he will ask to be transferred wherever he needs to be and that he will go to the ends of the Earth to find his brother.
Jimmy tries to keep up Ducky’s spirits, but he admits how hard it had been the first time he tried to find Nicholas, especially after finding out he died in a crash. Jimmy realizes that the travels Ducky took were to find Nicholas. As Ducky loses hope, the team comes in with presents. They have documents showing Nicholas has been alive the whole time and that his mother changed their last names. They tell Ducky his brother is in a nursing home and has early onset Alzheimer’s.
Ellie takes Ducky to the nursing home, where the nurse talks about how Nicholas is so happy. The only strange thing he did was weeks earlier when he took a bus to the post office. She tells Ducky he doesn’t have memories of his old life, but Ducky goes over to Nicholas. He gives him the train and then brushes his fingers through his hair like he did when they were young. Despite his ailing memory, Nicholas remembers his brother and is thrilled he got his letter. He stands up and the two brothers embrace.