When Adam's girlfriend, Tamiko, is kidnapped right in front of him, he shuts out Five-0 and breaks all the rules in order to get her back. Also, Five-0 investigates three seemingly unconnected homicides.

Harry Langford helps Five-0 investigate a series of murders that follow the plot of a fabled unpublished crime novel from the 1920s. Also, Tani and Junior's friendship takes a meaningful new turn.

While Five-0 investigates a murder on a cargo ship where pirates impersonated the Coast Guard to board the boat, Adam finally gets the evidence he needs to take down the Island’s Yakuza operation once and for all. Quinn helps Noelani when she suspects that her uncle didn’t die of natural causes.