When an escalating gang war spills into the stands of the local high school football game, injuring several bystanders and killing a gang leader, Five-0 uncovers an unlikely partnership between Samoan gangs and a mainland mob.
McGarrett places himself in the middle of a hostage situation on the USS Missouri. The hostage-taker is an ex-Navy SEAL suffering from post-traumatic stress disorder, who is the prime suspect in the murder of his wife.
Danny's ex-partner from the Honolulu P.D., is found in a luau barbecue pit. Danny demands the team must take his word the man was incorruptible, although evidence piles up ha was involved in corruption surrounding the Mexican Ochoa cocaine cartel. Internal affairs Sergeant Cage, who wrecked Chin's reputation, is on the case but fails to shield it as HPD Detective Ahuna discretely joins the Five-O investigation. The deeper they dig, the dirtier everyone looks. Jailed drug dealer Sang Min holds a trump card, so Danny bids on it.