Original air date: 10/06/2017 Runtime: 42:55 min. McGarrett and Five-0 work with an injured police dog who is the only witness to an ambushed drug bust. Also, McGarrett is visited by Junior Reigns, a former SEAL, who is looking to join the task force. Beulah Koale joins the cast as Junior Reigns.
Original air date: 10/20/2017 Runtime: 43:41 min. The lives of Five-0's informants are in danger when the HPD system is hacked and one ends up dead, forcing McGarrett to enlist the help of hacker Aaron Wright (Joey Lawrence), who he just imprisoned. Joey Lawrence Returns as Aaron Wright.
Original air date: 11/03/2017 Runtime: 43:44 min. At Halloween, Five-0 must investigate a string of murders that mirror stories from well-known Hawaiian folklore. Also, Grover is called to visit a man hours away from execution who may hold the key to a case that has plagued Grover for years.
Original air date: 11/10/2017 Runtime: 43:43 min. The murder of two tourists leads Five-0 to a man suffering from multiple personality disorder, where one of them becomes violent and another is a child. McGarrett is accompanied on the case by a stress management consultant, whom Danny and the others have hired to help him manage his health.
Original air date: 12/15/2017 Runtime: 41:50 min. It's Christmas Eve and Danny tells Charlie a bedtime story about a recent Five-0 case involving bad Santas and a holiday miracle. Real-life military veterans Jason Redman, Steven Jackel, Kathryn Taylor-Smith and J. Eddie Martinez guest star as veterans who help McGarrett with the case.
Original air date: 01/05/2018 Runtime: 43:16 min. When an FBI agent who was cracking down on organized crime is killed, McGarrett rounds up every gang-related criminal on the island to find the culprit. Also, McGarrett tasks Adam with forming a new division within Five-0 to take on organized crime.
Original air date: 01/19/2018 Runtime: 41:07 min. When the corpse of a diamond smuggler is stolen from a graveyard, Five-0 tracks down his partner, Voss, who will stop at nothing to retrieve their latest batch of contraband. Also, Adam recruits a new confidential informant, Jessie Nomura; Tani gets a devastating call; and McGarrett tasks Pua to find his and Danny’s stolen tools. Phillip Phillips and Christine Ko guest stars.
Original air date: 02/02/2018 Runtime: 43:41 min. McGarrett and Danny investigate the murder of a private detective whose client was killed the same way, and Adam sends Jessie (Christine Ko) into a dangerous situation with disastrous consequences. Also, Danny's uncle, Vito (Vincent Pastore), comes to town to help Danny and McGarrett get their restaurant up and running.
Original air date: 03/02/2018 Runtime: 43:39 min. Tani and Junior go undercover as prospective parents in order to infiltrate a private school where the headmaster was murdered. Also, Adam’s life is on the line when he is held captive and forced to produce a hidden massive amount of money.
Original air date: 03/09/2018 Runtime: 43:33 min. Adam’s mission to take down organized crime on the Island goes sideways when deadly chlorine gas he was using to bait a big fish falls into the wrong hands. Also, Adam begins to doubt Jessie’s (Christine Ko) allegiance. Christine Ko and Michael Imperioli guest star.
Original air date: 03/30/2018 Runtime: 43:45 min. The ex-wife of the man who shot Danny comes to Oahu and reveals how Danny's protection during a dangerous domestic dispute when he was in New Jersey helped save her life. Also, Tani and Junior are assigned to walk the beat as uniformed officers for the day, and Adam is framed for the murder of the crime boss he has been tracking.
Original air date: 04/06/2018 Runtime: 43:39 min. A hitman, Leroy Davis (Frankie Faison), McGarrett's father failed to arrest comes to McGarrett to finally confess his crimes and admit where he buried his victims. Also, Jessie makes a dangerous decision that could ruin Adam's life. Guest Stars include Frankie Faison, and Mixed Martial Arts Fighter Max Holloway.
Original air date: 04/13/2018 Runtime: 43:45 min. Catherine Rollins (Michelle Borth) recruits McGarrett and Jerry to help her track down a uranium deposit thought to be hidden on an abandoned Hawaiian island before a suspected terrorist can make dirty bombs with it. Also, when Junior falls and is trapped in a ravine, he reflects on his estranged relationship with his father.
Original air date: 04/20/2018 Runtime: 42:57 min. Harry Langford (Chris Vance) enlists McGarrett and Danny's help to track down Lady Sophie (Alana Boden), a teenage British royal who has run away while under his protection. Also, Grover, Tani and Junior work a 25-year-old murder case after a mysterious Betamax tape arrives at 5-0 headquarters.
Original air date: 05/11/2018 Runtime: 43:42 min. McGarrett joins Junior and his SEAL Team on a high risk covert mission to capture an elusive target who is holding his mentor, Joe White (Terry O’Quinn), hostage. Also, Gerard Hirsch (Willie Garson) and Kamekona help Grover and Tani on a murder case involving masterpieces stolen by the Nazis during WWII and Tani makes a shocking discovery. Terry O’Quinn and Willie Garson guest star.