The episode begins at the youth correctional facility, where Zack walks out and meets his family after serving his time. He hugs his mother and kids with his younger brother. They get into the car. Patricia tells her husband Brian that they are lost and they aren’t going the way they came. Zack looks worried and then realizes something. A car is following them and he asks his father to speed up. Three masked men get out of the van and drag Zack out of the car and leave. Next, Steve is at the airport to pick up his sister and he sees that she is now a caregiver and she has company with her; an old man named Morty and he will be with her as visiting Hawaii was on his bucket list.
Mary asks him about the secret that he couldn’t tell her over the phone and he tells her that it is about their mother. Doris opens the door and is disappointed to see that Mary didn’t come along with Steve. Steve tells Doris to give Mary sometime. Steve gets a call. The team is at the spot from where Zack was abducted. Brian tells them that Zack hacked into the White House database and took tickets to the correspondence dinner. And he was sentenced for six months. They don’t know of any fights that happened in prison. Brian says that he was following the GPS and landed where they are. Ho asks Charlie if it is possible to hack into a GPS and he says a yes but it is a sophisticated process and he needs to check. Kono notices the younger son James, who is still busy with his games on the tab and he doesn’t respond to her.
But then he shows her the tab and she sees that he has been typing a license plate number over and over again. The van was reported missing yesterday and it was logged back into the system 15 minutes ago. And its on its way to the HPD impound lot. Kono and Ho get to the van and open it; they find Zack’s body in it. Looks like their kidnapping case just turned into a murder! Max tells Steve and Danny that Zack died of cardiac arrest. He was suffering from arrhythmia and his condition worsened when he was subjected to torture. His fingers were broken one by one. He then points out to bruises on Zack’s chest that are consistent with CPR. This means they also tried to revive him. So the kidnappers actually didn’t get what they wanted out of Zack. Kono and Ho tell the rest that Zack was a good prisoner and kept out of trouble.
The only time he got into a shouting match was when Kong Liang visited him; Chinese national and a notorious cyber criminal and it is known that he makes between 25-50 million a year through cyber crimes. He hires the best experts from around the globe. He is like a ghost and very difficult to track. Danny knows a guy who could help them; Adam “Toast” Charles. Steve and Danny meet Toast. Toast tells them that Liang had invited him to join his hacker crew but he politely declined. He knows Zack as Omega Man. Steve tells him that Zack is dead. Steve and Danny wire him up and are about to send him to Liang. Toast tells them that he has glandular issues and that he sweats a lot. Toast doesn’t think that he can do this. He is too nervous. Danny tells him that everything will be alright.
Toast enters Liang’s office and he sees Liang breaking a hacker’s fingers and then giving him money to get it fixed so that he can get back to work. Liang asks Toast if he is there for a job and Toast runs screaming that he can’t do this. The team enters into the office and arrests Liang. Liang tells them that he did offer Zack a job as he was too good at what he did. But Zack didn’t want to disappoint his parents again and so he refused. But Liang tells them that he did not kill Zack and since Zack had hacked a lot of people before, anyone could be after him. Next, Doris finds her daughter sitting on her father’s grave and crying. Mary is angry at her mother for what she has put him through by faking her death.
At the HQ, Kono tells Ho that before Zack was sent to the juvi, he uploaded a file on an offline storage site and that the file is password protected which cannot be cracked unless they have the code as it is around 300 characters long. Ho thinks Kono should pay Zack’s parents a visit as Ho is sure that Zack must have definitely written that down somewhere. Kono goes to the Slater’s and checks Zack’s room. James arrives and Kono asks him if he knew where Zack kept the password and James starts telling names of some elements. Kono then checks a book which has the periodic table. She then calls Ho and tells him that Zack had his little brother memorize some elements and she wrote down the atomic number in the order. She thinks that is the password. She tells him it is 309 numbers. But just then Ho is surprised as the call suddenly gets disconnected.
Kono sees three masked men have entered the house and there is no service available on the phone. Kono locks James in the bathroom. One of them comes up and asks Kono to go downstairs. Ho tells Steve that he has a bad feeling about this. A cop arrives to check the Slater residence and he gets shot by one of the masked guys. The whole team arrives with a caravan. Ho tells Steve that a car is reported stolen and there is a print that was lifted off the previous stolen van and there is no math on Codis. Steve tells him to widen the search as these guys have used the hostages as shield and have jammed the phone lines. This means they are either civilian contractors or ex-military. Inside the house, the men remove their masks as they know they have time now. They then ask Brian about the password.
Outside, Ho tells Steve that the print matched to Sean Vincent, SA special force. He has a company now which specializes in covert black ops. They have a lot of secrets and maybe Zack stumbled upon one of them. Inside the house, Sean finds James in the bathroom and Kono’s shield is with him. He threatens to kill James and Kono comes forward and tells them that she is Five O and she has the password. She tells Sean to release the hostages; else he gets nothing. Sean then talks to Steve and asks him to back off and let him and his team, drive away with Kono and they can get their hostages. The men then step out of the house and put Kono inside a van. The driver sees that nobody is following them. Steve then slides out from under the van and plants a device on the door.
He then climbs up and then throws off the driver from the van and takes over the steering. Ho targets the device and blows off the door and shoots down Sean’s accomplices. Kono tackles Sean and beats him to the ground. At the HQ, they unlock the file and see that Zack had information about Desalvo, a mobster who had escaped from protective custody. Sean and his organization helped him disappear and killed anybody who found out about Desalvo. The team tracks down Desalvo and arrests him. At the HQ, Kono thanks James for his help and lets him keep hr shield.
Next, Morty and Mary are at the beach and he asks her to go see her mother. He tells her that she is lucky to have a second chance. He also tells her how he had a fight with his daughter and didn’t speak to her for years and then one day he received news that she is dead. Mary goes to meet Doris. They hug each other and cry. Steve smiles. The episode ends.