At his mentor's request, McGarrett persuades Max to redo the autopsy on a SEAL, thought to have committed suicide, in order to investigate his murder. Meanwhile, Chin Ho worries about Kono hanging out with a group of dirty ex-cops, including Frank Delano.

McGarrett finds himself in need of the Five-0’s help when he goes to North Korea with Jenna Kaye to deliver a ransom to rebels who are holding her fiancé hostage. Meanwhile, the Five-0 investigate the murder of an investigative reporter who seems to have ties to Jenna.

McGarrett must help his mother execute a covert op to retrieve an incriminating microfiche. Meanwhile, Kono’s life is in danger when she closes in on Adam’s secret.

Steve and Catherine are still reeling from the murder of one of their ohana and, along with Danny, Junior and some old friends, Harry Langford and Wade Gutches, hunt down the killer. Also, Tani and Grover investigate when a bag of human bones, discovered inside an abandoned storage locker, goes missing.