The episode begins with a security guard chasing two trespassers, but ends up falling in a ditch. The trespassers shoot the security guard. Danny and Grace are waiting for Gabby the airport when Danny receives a message from her. It appears that Gabby has cancelled her plan. Grace feels bad for Danny. Danny then gets a call from work. The team arrives at the latest crime scene. Ho tells Steve and Danny that the victim is a security guard, Chad Torrez, who worked at a construction company. The company was doing a geological survey. According to the supervisor, Torrez was out on patrol when he reported about two trespassers.
Kono arrives and tells them that HPD found some fresh tire tracks. She tells them that the according to the foreman, the holes weren’t there till a couple of days ago. They figure out that the perps dug the holes. Max finds the skeletal remains of a human thumb. He thinks that the perps were looking for a dead body, and clearly it has been removed. They theorize that the hole was a grave. They decide to check the other holes. Later, Max tells the team that there were 11 holes which contained dead bodies which have been there for six months to 18 years. Steve figures out that the suspects have been using this field as their personal graveyard for about two decades. The first guy they identified is Jim Henley, who went missing seven years ago.
It turns out that Henley was a confidential informant for the Yakuza. Then there are Ken Nagoya and Stacey Ford, who were eye witnesses for separate homicide cases against Yakuza members. Both of them disappeared. So, this field was a body dump. Catherine arrives to meet Steve. She tells him that Kevin Hobbs, who works with the FBI, called her and told her something “off the record” which she thinks he really needs to know. She hands Steve some papers to go through. Danny tells Kono to talk to Adam and find out if he knows anything about this field. On his way out, Steve tells Danny that he needs to take care of something.
Danny wants to what is going on. Steve tells him that the FBI’s computer forensics unit learned that somebody has been hacking into the national fingerprints database, and now they have a suspect. It is his mother, Doris. The feds have managed to track the IP address to the WiFi spot, and have managed to place Doris there around that time. Steve meets Doris and asks her what is going on. She tells him that she can explain everything over a cup of coffee. Steve hears some noise coming from one of the rooms. He goes to check, and finds two men working on some plan. He sees that the walls are covered with blueprints. Steve demands an explanation. Doris tells him that she is trying to find out who stole the microfiche.
She also tells him that she found partial prints at the scene of the break-in, and that is why she hacked into the fingerprints database. She refuses to disclose the name of the suspect. She wants to steal back the microfiche, without which they are vulnerable. At the HQ, Ho and Danny tell Kono that three other bodies have been identified and it turns out that Adam’s brother, Michael, was a suspect in two of those murders. Danny and Ho go to meet Michael, but Michael lawyers up. At home, Doris and her two buddies tell Steve that the prints were a match to a guy named James Austin. James is ex-military, dishonorably discharged. It turns out that James was hired by Tyler Cain. They tell Steve that initially Cain worked with the CIA, but then he started his own military company.
Now, Cain is about to be appointed Director of National Intelligence, which requires Senate confirmation. Steve theorizes that when Cain was with the agency, he did things that the Senate wouldn’t approve of, and that is why he stole the microfiche. Cain is holding on to the microfiche for leverage. They tell Steve that Cain keeps it in his office which is on the 16th floor of the Honolulu Tower, which is heavily guarded and has cameras all over the place. Moreover, one requires a key card for any sort of access in the building. Doris explains to Steve as to how she and her friends, Wade and Mick, have managed to put together a strategy to get the microfiche.
Steve doesn’t agree to this. Doris tells him that they are executing their plan tonight. At home, Kono meets Adam and asks him why he met Sato. Adam tells her that he is trying to completely cut off ties with the Yakuza. She then asks him about the body dump. He swears that he doesn’t know about any such field. Kono looks relieved and leaves. In her car, she hears a phone ring. It is a clone of Adam’s phone. She hears Adam telling someone that he got a visit from “Five O”. The man on the other side of the line fixes a meeting in two hours. Kono calls Fong and tells him to ping the number Adam just called. Later, Kono arrives at Pier 38. She finds some barrels and cuts open one of them. It contains the dead bodies that were dug out from the field.
Two men arrive at the warehouse and a gun fight ensues. Kono guns them down, but she also ends up getting shot. She makes a 911 call, and passes out. Later, the team arrives at the scene. The paramedics take Kono to the hospital. Danny tells Steve that the guys Kono shot, worked for the Yakuzas, and they took orders from Michael, but there isn’t enough proof to arrest Michael. They used the same guns that were used to kill Torrez. Danny then asks Steve about Doris. Danny tells Steve that he should help his mother. Steve agrees. Later, Steve and Doris manage to get inside the building. Mick hacks the security systems and Wade is in charge of transportation. At the hospital, Adam arrives to meet Kono. He tells her that after she left, he made some calls to find out about the field.
He tells her that Michael might be involved. He tells her that he was trying to protect her, but ended up putting her in danger. Kono tells him that she has something to tell him. She is about to tell him when the nurse arrives and takes her for a CT scan. Adam tells her that he will wait for her. Adam’s phone rings. At the same time, the cloned phone rings as well. Adam figures out that Kono cloned his phone. At the Honolulu Tower, Steve and Doris are in the elevator shaft, awaiting Mick’s signal. Doris uses the key card to show Steve one of her magic tricks. Mick gives them an all clear, and they enter Cain’s office. They manage to get the microfiche but the sensors go off. Steve tells Mick to hack the camera feeds.
Wade, who is flying the helicopter, tells them that there are two heavily armed guards on the roof. Steve and Doris are unable to escape. Steve distracts the guards, but Doris gets caught. As per Doris’s instructions, Mick bails out. He tells Steve that Doris is caught. Cain arrives. They find the microphone on Doris and Cain tells her partners that if he doesn’t get the microfiche, he will kill Doris. Steve tells Mick that he is not going to bail on his mother. Cain arrives in his office with Doris and his guards, and sees that Steve is already there. Steve destroys the microfiche and tells Cain that people know that he and Doris are in the building. He points out to the fact that Cain anyways did not want the world to know about the contents on the microfiche.
So, since it is destroyed, there is no reason for him to kill them. He tells Cain to let them go, else people will figure out what could have happened. Cain lets them go. Steve tells Wade to pick them up. In the elevator, Steve pulls out the microfiche from his sleeve. He used the magic trick his mother taught him when he was a child. Doris laughs. They go home. The next day, Max tells Steve and Danny that he pulled out a slug from one of the dead bodies recovered from the barrels. The ballistics shows that the bullet was fired from Kono’s gun. Steve and Danny are shocked. To be continue.