Original air date: 09/25/2015 Runtime: 44:14 min. A murder leads Five-0 to investigate a centuries-old Oahu palace raid involving pirates, buried treasure and a killer who is using a stolen painting as a map. Also, the morning after their wedding, Kono and Adam are threatened and tortured by Gabriel, and Danny shows concern for McGarrett regarding Catherine's return to the island.
Original air date: 10/02/2015 Runtime: 44:13 min. Five-0 investigates when a bomb squad is attacked and the culprit threatens to detonate additional hidden explosive devices unless arsonist Jason Sinclair is released from prison. Also, after Adam returns from the hospital, Kono realizes that they are being watched, and McGarrett prepares to take his relationship with Catharine to the next level. Former UFC Champion Randy Couture returns as Arsonist Jason Sinclair.
Original air date: 10/16/2015 Runtime: 44:14 min. 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. Jerry Rice guest stars.
Original air date: 10/30/2015 Runtime: 43:24 min. It's Halloween in O'ahu, and Five-0 must track down a serial killer inspired by Frankenstein. Also, Jerry calls Five-0 for help when an armed gang raids a blood bank, and Danny must track down Grace who lied and snuck out to a Halloween party.
Original air date: 11/06/2015 Runtime: 44:13 min. McGarrett's first date with Lynn (Sarah Carter) on a deserted island turns deadly when a mob boss hiding there hunts them down in order to keep his location a secret. Also, Chin, Kono and Grover must race against the game clock to locate the father of a high school football star who will be murdered by a local gambler if his son doesn't throw the big game.
Original air date: 11/13/2015 Runtime: 44:12 min. Five-0 must work with charming con man Hank Weber (Kristoffer Polaha) to find a killer when his female partner is murdered on the job. Also, San Francisco Police Inspector Abby Dunn (Julie Benz) comes to O'ahu and works with Chin to investigate the murders of five Chinese arms dealers.
Original air date: 03/11/2016 Runtime: 43:38 min. McGarrett and Five-0 must track down a Russian spy who has stolen a flash drive containing classified NSA information that puts the life of a member of their Ohana at risk. Also, McGarrett finally learns why Catherine left him, and Abby continues to conceal her actual mission from Chin.
Original air date: 04/01/2016 Runtime: 43:07 min. When a man is found left for dead drifting off the coast of Oahu, Five-0 uncovers a deadly slave trade operating aboard an illegal fishing vessel. Also, while Danny is out with his children, his car is stolen so he commandeers a bus to chase down the thieves.