A woman seeking to leave a team-building retreat out in the woods gets a shock when she runs into a wounded man dressed in ancient Hawaiian clothing. He falls right in front of her and she screams. Meanwhile, Danny is attempting to cook in Steve's apartment, much to the latter's chagrin.
The team discovers that the man was a member of a group which re-enacted ancient Hawaiian tribal sports. Steve knows the leader of the group, and manages to get a name for the victim: Brandon Koruba. He was supposed to take part in the gathering, but never arrived. No one in the club had any grudges against him, and by all accounts he was a good man. So why was he killed?
Kono finds an old Hawaiian artifact at the crime scene, but no one is able to identify what it could be. Koruba's wife also has no idea why her husband would be murdered. She can't identify the artifact either. Steve and Danny go to the museum, and the curator (Gabby) explains that some of the accessories Koruba had on him might be worth hundreds of thousands of dollars. Motive enough to kill him, thinks Steve. Steve also thinks that Danny should ask Gabby out.
Chin finds out that one of the men in the re-enactment club is known for taking similar items and selling them off. The team tracks him down, but the police is already trying to clear him off from squatting in an abandoned building. Steve smokes him out with tear gas, and in the man's house is a copy of the missing museum artifact, which is covered in blood.
The thief admits to stealing the artifact from Koruba's body, but not to killing him. Meanwhile, Kono finds out that Koruba's last phone call was with his business partner, Tony Dennison. Steve and Danny talk to Dennison, who claims to have called Koruba about some information about their ships. Dennison also points out that environmentalists are frustrated with them because their ships pollute the waters and kill marine life. The team uncovers a video made by an environmentalist group which names Koruba as their first victim.
Through a fingerprint match, the team uncovers the identity of the masked man in the video: Kevin Creed. Creed is captured, but his lawyer has an alibi for him. Also, since Koruba didn't renew his shipping contract, there was no motive for Dennison to kill him. Steve is surprised that he hadn't heard about this before.
Mrs. Koruba has learned about the lack of permit renewal and when Steve and Danny arrive at the Korubas' home, they find Koruba's widow holding a gun at Dennison. It looks like both she and Dennison were behind Koruba's murder because he didn't want to renew the permit for the shipping company. Killing him would allow Dennison and the wife to keep the shipping company active. Dennison takes the widow hostage, but Steve manages to shoot Dennison in the shoulder.
Later, Gabby and Grace are bonding at Danny's dinner party, and Steve urges Danny to join them.