Hana Mao ‘ole ka ua o Waianae (Endlessly Pours the Rain of Waianae) – In the Season 9 finale, Five-0 continues to hunt down escaped criminal Aaron Wright before he can sell cyber-weapons to the highest bidder. Also, the lives of McGarrett and the team are put in danger when a visitor comes to headquarters to make amends.
Ho’okahi no la o ka malihini (A stranger only for a day) – McGarrett helps his visiting sister, Mary, spy on her shady neighbors, while Five-0 investigates the murders of a ride-share driver and his passenger. Also, the team teases the youngest members of Five-0 when Junior escorts Tani to a wedding.
O ke kumu, o ka mana, ho’opuka ‘ia (The teacher, the pupil— – Adam examines the murder of an FBI agent who is about to marry a Yauka leader’s daughter. Noelani is held hostage.
He kama na ka pueo (Offspring of an Owl) – Five-0 investigates the murder of a man whose body may hold the key to a 20-year-old case involving a kidnapped girl whose father never stopped looking for her.
Pupuhi Ka He’e o Kai Uli (The Octopus of The Deep Spews Its) – The team looks into the murder of a window washer. Later, Adam and Grover investigate the murder of a gambler.
Hapai Ke Kuko, Hanau Ka Hewa (When Covetousness is Conceived, Sin is Born) – The top salesperson for a beauty company-pyramid scheme is murdered, and Five-0 sifts through a long list of possible suspects who would want her dead. Also, Adam befriends a homeless man estranged from his family.
E’ao Lu’au a Kualima (Offer Young Taro Leaves To) – Junior is torn between his duties as a member of Five-0 and his feelings for his former girlfriend when her new love, the father of her son, is one of the culprits in a bank-heist-turned-homicide.
Ho’opio ‘La E Ka Noho Ali’i a Ka Ua (Made Prisoner – As a dangerous hurricane hits Oahu, Five-0 is tasked with protecting El Diablo, a captured serial killer who is being hunted by an assassin. Also, Tani’s civilian safety check during the storm turns deadly and Rachel and Charlie evacuate to Danny’s house, where the ex-spouses reminisce.
Ikliki I Ka La O Keawalua (Depressed With The Heat of Kealwalua) – While investigating Flippa’s friend’s murder, McGarrett and Grover uncover a deadly plan by an extremist group on the Island. Also, Grover has an emotional reaction to the case.
Ke Iho Mai Nei Ko Luna (Those Above Are Descending) – Adam, Junior and Tani travel to the bottom of the Pacific Ocean when a murder takes place in a remote underwater lab, and the killer may still be on board
Ka Hauli o Ka Mea Hewa ‘Ole, He Nalowale Koke (A Bruise Inflicted on an Innocent Person Vanishes Quickly) – MacGarrett and Five-0 support Danny and Rachel by determining what happened when gets into a life-threatening car accident and lands in critical condition. Also, Tani helps Koa when his rehab patient goes missing.