The episode began with the shotgun murder of a couple living the lavish lifestyle.
When Five-0 arrives on scene, they discover all security cameras have been deactivated. Expensive jewelry and money lie visible on tabletops, so theft is not the reason for the murder. There is also a baby crying upstairs. Danno goes to comfort her, saying he is sure she is frightened.
Upon investigation, Five-0 discovers that the couple is Dr. and Mrs. Philip Van Horn. The Van Horns inherited old Hawaiian money.
Max distracts McGarrett long enough to tell him he has found the elusive gift McGarrett has sought after for Catherine’s naval ceremony. She is being honored on her last day in the Navy. The catch to the gift is that it will cost McGarrett $1300. A stunned, reluctant McGarrett pays Max for the find.
Max informs the team of his findings. The couple was shot at close range with suppressors. McGarrett surmises it must have been a professional hit. As they discuss the case, Mrs. Van Horn’s sister arrives to identify the body. She takes custody of the couple’s baby but leaves the team no closer to solving the murder.
Upon investigation into the family’s insurance company information, Chin discovers that there is a family trust, and Philip Van Horn’s wayward brother, who has a long history of drug charges and arrests, is the beneficiary. Further, people going into and out of the house were assigned access codes, and Philip’s brother’s code was the one used on the night of the murder. McGarrett and Danno arrest the brother and find out he sold the code to a complete stranger at a bar.
In going through the insurance company’s previously photographed items from the house, Chin discovers everything is accounted for except one item, a scrimshaw related to the crest of the Royal League, an association that was disbanded 70 years ago in which Jonas Van Horn, the family patriarch, was a member. Chin knows someone who can help with the investigation, but hesitates to share his name. However, there is no other choice, and Chin must introduce Danno and McGarrett to his source, Jerry.
Jerry tells the team the scrimshaw is a key that opens a lock to a 700 year-old priceless treasure, the Medici Rings, which were stolen from Italy in the 1800’s and were perhaps smuggled into Oahu.
Duke calls McGarrett with news that Philip’s brother remembered the name of the stranger who bought the code. It was Griffin Moore.
McGarrett and Danno track down Moore and find modeling clay, some plastic, and a skeleton with a gunshot wound to the back of the skull. The skeletal remains are later found to be those of Griffin Moore.
McGarrett and Danno return to headquarters and find Jerry outside staring at the statue of King Kamehameha. Jerry informs the pair that the Rings went missing about the time the statue came over to Hawai’i, around 1880. He believes the Rings may have been smuggled inside the statue. In that case, McGarrett reckons, the original statue would have to be swapped with a fake so that it could be taken apart. Recalling the modeling clay and plastic at Moore’s, McGarrett believes Jerry has a valid idea. However, when he tells this to Jerry, Jerry informs him that this is not the original statue. The original sank on a ship on the way over. It is now on Hawai’i at the North Kohala Convention Center.
Jerry hands McGarrett some paperwork which he believes contains a code of some kind, after which the three travel to the Convention Center, where they find a fake statue. Moore has already made the switch. McGarrett takes the paperwork to Catherine with the chance she might locate a code of some kind. When they later visit her at Naval Intelligence, she deciphers the code, which tells the team that the treasure they seek is hidden inside the statue’s left foot.
Chin finds out that a City Maintenance truck was stolen two nights before the murder. He pulls footage and runs facial recognition, identifying the three killers of the Van Horns. He traces them to their arrival and location on the Island through a van rental. McGarrett and Danno go to the address, where they arrest one of the three gunmen. They also find the original statue.
The gunman tells McGarrett and Danno that the other two gunmen are at the Museum of Art, where the scrimshaw has been donated for display. They get to the museum in time to catch the killers in the act of stealing the scrimshaw.
McGarrett lets Jerry have the honor of opening in the foot of the statue, and Jerry is proven right. The Rings are inside the foot of the statue.
McGarrett meets Catherine prior to her ceremony and gives her the gift – an original pressing of a Chicago album. McGarrett tells her he remembers that her mother used to play that for her when she was afraid. He then tells her she has nothing to be afraid of in leaving the Navy for the new job. He tells her he is right there for her.
Danno stops by the house where the Van Horn baby now lives with her aunt and gives her Grace’s old stuffed monkey.
Switching back to Catherine’s ceremony, as Catherine holds her award in front of her and the crowd applauds, McGarrett catches Catherine and her new boss, Billy, as their eyes lock on each other.