Five-0 is called in to investigate the third in a string of arson attacks on boats belonging to Oahu Shark Tours. The investigation takes a dark turn, however, when the body of Jason Benn, a Shark Tour employee, is found in a submerged shark cage in the ocean, not far from the burned boat. Max examines Benn's body and determines that he was killed via blunt force trauma, so Five-0 combs through the evidence to track down Benn's killer. Shark Tours seem to be universally hated by locals, so the team faces a mighty task narrowing down the suspect list. A retaliatory case of arson initially points the blame at the Kapu, a local surf club, but after McGarrett and Danny talk to their leader, Kawika (ep 106, 122, 212), it's clear that they had no involvement in the bombing. Later, Fong discovers that the device that triggered the fire on the boat was actually a modified pet food dispenser, and that a local drug dealer had been a suspect of interest in previous arson cases. Chin Ho and Kono track him down and interrogate him, but he has an alibi that checks out. A break in the case comes when they find an arm belonging to Hal Lewis, a local fisherman, in the belly of a reef shark. Lewis, along with Jeff Lappert and Bruce Kaneshiro, co-owned a ship called the Chandler, which forensics placed at the scene of the original arson. When Kaneshiro turns up dead and the team locates a damp container that was used to transport a large amount of MDMA at Lewis' residence, the attention turns to Lappert. Five-0 tracks Lappert to a potential drug deal with Taiwanese cartel members and, after a shootout with the cartel goons, McGarrett arrests him for murdering Benn and his two friends.
Meanwhile, Kamekona spends a lot of time playing helicopter flight simulations in hopes of earning his pilot's license. Danny thinks that the big guy won't be able to get his license for a while, but much to his dismay, Kamekona aces the test. The episode ends with Danny, Max, and McGarrett taking the inaugural flight in Kamekona's helicopter.