The scene opens in Waikiki Beach in O’Ahu where a girl swims and suddenly is about to be attacked by a shark, but it is only her brother. He goes underwater and sees a hand floating. Meanwhile, Kamekona gives Steve and Joe his new menu items to his Seafood truck. Steve asks Joe about the video of his father meeting with the Senator and Wo Fat. Joe says that he is trying to get the audio with him, but it is hard. He tells Steve to wait for it. Steve gets a call and he and Danny visit Max who tells that they have a hand. Max takes off the skin and puts it on like a glove. He gets a match to the victim who lost a hand. His name is Blake Spencer. They get the address and tell the owner of the bar at the address. He says that Blake rented the apartment upstairs. The man says that Blake was a diver and that he was a good one too. He says that Blake mentioned on a dive that he was gearing up for.
They go into his apartment and find that Blake spent thousands of dollars on equipment. Danny finds a book of codes. They hear something and find that there are doubloons in a tank and Steve says that Blake must have found that big treasure and that it got him killed for it. Lori goes to the nursing home where Blake’s mother is at. She sees that Blake’s mother is still stuck in the time when Blake was six years old. Meanwhile, Danny and Steve go to a museum and meets Dr. Gabriella Asano and Danny takes a liking to her. He shows the coins to her and she recognizes the coins from Spanish ship. She says that the treasure should be authenticated. Steve says that it is evidence and Danny says that she can have one coin. Steve tells Danny that he should ask Gabriella out for coffee and tells him that he needs to get back on the horse. Steve makes a stop and talks to Kat Rollins about the code book they found. She says that she will tell him where the coordinates are. Steve also asks her to check on the status of the video that was submitted to the DOD by Joe. She agrees.
Chin Ho tells Steve and Danny about how Max found the rest of the body and that Blake still had his dive bag with him. Lori tells that Blake’s mother has Alzheimer’s and she didn’t tell her about Blake. Danny tells that the museum showed that there is more motive. At the Medical Examiner’s office, Charlie tells Chin Ho that he only recovered a wallet that has been down in the water for 50 years. Chin Ho asks Charlie a favor and shows that there was a login to his police account from an IP that he doesn’t recognize. He says that he will report it if it is worth it. Charlie says that he will do what he can do. Lori goes up to Jimmy Koller, a diver. She asks if he knows Blake Spencer and he says that Jesse Billings is a man who sank a lot of money into finding “The Princessa”. They watch a video and see that Blake was one of Jesse’s divers. They go and visit him and he says that he didn’t kill Blake and says that he was his best divers. Danny gets a call from the museum and says that they Spanish Galleons that were found are fake. Jesse says that he didn’t know what Blake knew that they were fake.
Chin Ho gets word that the IP belongs to Kono. Chin Ho says that he remembers logging in to her computer. As for the wallet, Charlie shows Chin How that it is money from when Hawaii made their stamp to go on the money. The bills were recalled. Steve show the coordinates that Blake went and Lori says that she has an idea on how to find which route Blake last took. They go to Moana Charters and Lori asks the manager, Remo Julian, to find the boat. However the boat’s transmitter is busted. The coast guard searches for the boat while at headquarters, Danny asks if the relationship status is empty does that mean something. Lori tells that he should asks her out. They get word that they found the boat and Steve says that he is going to take a partner. They get on the boat and Joe thanks Steve for calling him to join him on the dive.
Chin Ho goes to Kono’s and asks why she used his password to get into HPD. She says that she wanted to see her file. She tells him that he shouldn’t be there. Ray Mapes comes up and Chin Ho tells him to leave. Ray asks Kono if he should leave and she tells him that he can stay. Kono and Ray go inside where Frank Delano is there. He says that he doesn’t know if using Chin Ho’s password was smart or stupid. Kono tells him that she got him the information that he needed. The Five-O team arrives on the boat and there is blood and a bullet from a 9mm. Steve and Joe get ready to dive and Steve asks about the video again. Joe tells him to clear his mind about it before they dive. They get down in the water and find a car at the bottom of the ocean. They look inside and there is a skeleton inside.
They pull the vehicle and body up and Max says that they have a full skeleton intact. He says that he doesn’t know if they can identify it because records don’t go back that far. Joe says that he can take Max to JPAC and get it looked at. Max is excited. They get there and Max is overjoyed and says that JPAC is like his “Graceland”. Back at headquarters, Steve shows that a man named Robert S. Murphy was a dead body being transported that he found in an article. Lori says that she remembers seeing a picture of the man. They get to Blake’s mother’s room and they find out that the man is Blake’s grandfather. Joe says that the remains belong to Miles Brodick. Joe tells that Brodick was a criminal and that he was a cemetery worker where the money was burned except for $2 Million of it. Chin Ho comes up and says that Remo was lying about the transmission was fine. He says that there were two boats where Blake was.
They get in Remo’s place and find everything cleared and Danny says that he found the body of Blake’s grandfather. They find the coffin and Remo is inside, dead. Max comes by and takes pictures. He sees that there is there is an impression. Lori sees that the impression is from the U.S.S. Pegasus. She says that Jimmy Koller is the killer. They get to where Jimmy is packing up and Steve and Lori manage to get him. They take him back to headquarters and he admits that he killed Blake and Remo because they were going to stiff him on the cut. Lori tells that she is going to make the notifications and Steve offers to make them, but Lori says that she will do it. Kat comes into Five-O Headquarters and Steve asks her why she is over-dressed. She says that she is being sent to the Gulf. She says that she is leaving tonight and tells that DOD has never received the video. Meanwhile, Danny asks Gabriella out for coffee. She accepts.
Chin Ho goes to Kono’s again and tells her that he wanted to apologize to her. He says that he has been through everything that she is going through and says that she was the only person who stood by him all through it. He says that when she wants to talk about it, he will be there for her. The next day, they load the body of Blake’s grandfather onto a plane and they all salute. Steve tells Joe that he knows that he never sent the video. He says that he knows that his father was Joe’s friend, but he was his father. Joe says that Steve’s father is not the only one he is trying to protect, but Steve says that he needs to know.