Five-0 investigates when a wealthy recluse is found dead in a remote field with nearly one million dollars in counterfeit bills. Also, Adam is kidnapped by the Yakuza and forced to torture one of Gabriel’s men.

When the bodies of two serial killers are found on Five-0 property with chess pieces in their mouths, McGarrett and the team hunt for a vigilante as fear grows that tourists aren't safe in Hawaii.

Five-0 investigates when a plane that mysteriously crashed into the Pacific in the ‘80s is found, but with a recently murdered scuba diver inside. Also, as MacGarrett and Quinn zero in on who planted the bomb in his garage, and he formally asks her to join Five-0, she is arrested for money laundering.

It's Halloween and Five-0 investigates a home invasion turned deadly after a dangerous "monster" escapes from the basement. Also, Max returns to Oahu with a very special guest.