A ship full of dead bodies sends Five-0 to the island of Lanai where McGarrett (Alex O'Loughlin), Danny (Scott Caan), Chin (Daniel Dae Kim), and Kono (Grace Park) believe Yakuza big wig Michelle Shioma (Michelle Krusiec) has set up a new drug smuggling operation. Captured by Shioma's men, but still outgunned, it takes Jerry (Jorge Garcia) sending in the cavalry to save the day, which also earns Five-0's special consultant the prize he's been waiting years for.
The episode's B-story sends Grover (Chi McBride) and his son (Chosen Jacobs) to Chicago for a little male bonding and allow Grover to testify at Clay Matthews' (Mykelti Williamson) hearing. The more emotional of the two stories, Grover's homecoming is bittersweet given old friends on the force aren't happy with his return. The subplot does offer some nice father/son moments between the pair, and a lesson from father to son about doing what is right - even if it's the harder path.