On the last episode of NCIS, an Admiral is working when he opens an e-mail that turns out to be a virus. It blocks him from accessing his data and it claims that he should by a decryption key.
Meanwhile, the team minus Alex are getting requalified with weapons training and Tim is impressed with Gibbs using his father’s old weapon. They are surprised to see that the Vice Admiral wants to see Tim so he heads off.
We see Alex at her mother’s home after getting a 911 text. However, it appears to be a false alarm. Her mother, Marie, reminds her about dinner for her father’s birthday the next night.
At the Admiral’s, Tim tries to explain to him what ransomware is and how all he has to do is pay the $500 for it to be taken off his computer. He really wants Tim to get the virus off, even though Tim tells him it isn’t possible.
When Tim gets back to work, everyone has just finished talking about how the shooting range went. Nick asked Alex about where she was, but she refuses to talk. Tim gets a text from the Admiral only to find when he opens it, he has been given the virus. Before he can warn everyone to get off the wifi network, they are all infected.
Vance scolds the Admiral for infecting Tim’s computer with the virus. Tim had been able to prevent the virus from spreading to everyone else in the building and they wait to find out why the Admiral hacked him. He tells them they would have to find the location of the server to shut it down. Since this now hit government agents, Vance wants them working the case.
The team has burner phones until they can get their new smartphones. Since the hacker has hopped onto different IP addresses in Russia, Clayton offers to call up a fellow MI-6 operative stationed there in MTAC. He tells Gibbs, Tim and Clayton that whoever the hacker is most likely would be American since the grammar was perfect. He directs them to his counterpart in Langley who could be their last hope for help.
Alex is working when her mother shows up with Nick. She had remembered Alex borrowed her crockpot and she needed it for dinner the next night. Charmed by Nick, she invites him to dinner but Alex claims he has a mission he is preparing for.
Ellie and Clayton go to talk to Asher at Langley. However, when he spots what the virus is, he begins to act strange. Claiming that he’ll look into it and get back to them, the two agents are doubting he is legit. Deciding to bring him in for interrogation, they return to find Asher is gone.
Ellie tells Gibbs that Asher completely disappeared off the grid and they can’t find him. Tim and Abby are looking into traffic cams to see if they can spot him. Meanwhile, Alex and Nick get into the office, where they discuss her relationship with her mother. Nick feels like there is something else about the relationship she won’t discuss, but Alex shrugs it off.
Ellie talks to Asher’s wife, who believes her husband is a good man. She gives Ellie permission to look into his home computer. Down in the lab, Abby tells Gibbs she was able to use Asher’s satellite radio to find him. Since Tim can’t use GPS to get to the location, they remind him to use a map. She was also able to find he had stopped at a self-storage facility.
Tim and Ellie arrive at the location of the car and find nothing there. But then she notices what appears to be a car in the water. At the self-storage place, the owner claims no one with Asher’s name rented a storage unit but then Gibbs notices security cameras.
They are able to see that Asher arrived with someone but then he left alone the next morning. After finding the storage unit is empty, Gibbs gets a call from Ellie about finding the car. When they arrive to see the car has been pulled from the water, they get the trunk open and find his body has been frozen solid.
In autopsy, Jimmy has to drill into the body in order for them to read his temperature. Because he can’t force the body to defrost, Ducky must wait days to even do the autopsy. We also see the virus replicated and Jimmy was hit with it as well.
In the lab, Ellie and Tim are working while Abby does a demonstration with liquid nitrogen to show what happened to Asher’s body. While they do not know how his body was frozen, Ellie was able to find a possible lead to a cryo-therapy spa that ordered a lot of liquid nitrogen.
Up in the bullpen, Alex and Nick have Asher’s college records. He had been kicked out for creating the ransomware virus and it was named after his dorm. They also found the name on the storage unit came back as an alias and the address was fake. Nick realizes the facility manager would have known that. They head off but Alex stays back on a phone call with her mother.
Ellie and Tim go to talk to the employee at the spa and based on the number of containers ordered, he deduces they have more than 500 customers a week. But they actually don’t have that amount and she admits her manager sells some of the liquid nitrogen to David Yates, the same person who rented the storage unit.
At the facility, Buzz continues to deny knowing anything to Nick but after prodding from Gibbs, he admits there is a second storage unit Yates rented and he doesn’t know what is inside. When Nick and Gibbs investigate, they find an cryospa with two bodies inside.
Going to her mother’s home, Alex realizes her mother is having issues with her memory. She reminds her that her father passed away a few years earlier.
In autopsy, Ducky and Jimmy have not been able to do the examinations yet but they did find the two homeless men were frozen alive. Back up in the bullpen, the Admiral comes to apologize to Tim and wants to pay the ransom. However, Tim tells him to wait. Ellie then tells Gibbs upon his return that Asher’s roommate, Carlo Hackett, had also been kicked out due to the ransomware virus.
He had been a lab tech and was buying the liquid nitrogen to work in the field of cryogenics. In order to continue his work, he brought the ransomware virus back to make money. They go to the storage unit where Hackett arrives. Tim and Gibbs get him to deactivate the ransomware.
In interrogation, Ellie is not impressed when Hackett claims that they will kill his “test subjects” once they thaw.
At her mother’s, Alex has a heart to heart about her mother’s battle with her memory. Alex is encouraged to fight but her mother fears forgetting her daughter one day. She assures her mother she could never be a burden to her.
Back at the shooting range, Gibbs and Alex talk about the development with her mother. She reveals she has decided to move back home to take care of her.