Ke Ala O Ka Pu (Way of the Gun) – Five-0 must locate a teen girl who purchased a gun from a junkie, and discover that the firearm, over the course of decades, has affected all of their lives.
Ai no i ka ‘ape he mane’o no ko ka nuku. (He who eats ‘ape – Tani and Junior go undercover at a gym to track down a deadly batch of steroids that’s killing users, before the drugs claim any more victims. Also, Danny and MacGarrett sub as bodyguards for Danny’s high maintenance ex-mother-in-law, Amanda Savage, a wildly famous romance novelist with whom he has never gotten along.
Pio ke kukui, po’ele ka hale (When the Light Goes Out, the House is Dark) – After fighting off an assassin in his own home, McGarrett and Joe White flee to Montana to prepare for a battle against those exacting revenge for a past SEAL mission.
Mai ka po mai ka ‘oia’i’o (Truth Comes From the Night) – A renowned urban vigilante is killed after making another citizen’s arrest, and Five-0 delves into the world of super heroes and comic books to find the killer. Also, Adam finally gets closer to finding out who killed his sister.
Pua a’e la ka uwahi o ka moe (The Smoke Seen in the Dream Now Rises) – McGarrett investigates a cold case from the 1940s, one that his grandfather and Honolulu detective, Chang Apana, worked on, and he tries to deduce how the case could have been solved. Also, McGarrett and Danny get ready for the opening of their restaurant.
Mimiki ke kai, ahuwale ka papa leho (When the Sea Draws Out the Tidal Wave, the Rocks Where the Cowries Hide are Exposed) – Crime spikes when a heat wave hits Oahu, causing McGarrett and Danny to hunt down a bank thief, and Tani and Junior’s car is stolen while they’re on duty. Also, Grover plays the golf game of a lifetime, and Kamekona incites a riot by price-gouging on his shave ice.
Ka ‘owili’oka’i (Cocoon) – The Season 9 premiere: After Steve’s CIA agent friend is killed, McGarrett lets himself be captured by the group he thinks is responsible and endures a torturous sensory deprivation tank to find the killer. Also, Tani wrestles with whether or not she will tell McGarrett about the murder weapon she found at Adam’s house.
Waiho wale kahiko (Ancients Exposed) – In the Season 8 finale, McGarrett and Five-0 discover a Russian spy ring hiding in plain sight when a Russian nuclear attack submarine appears off the coast of Waikiki. Also, Tani is conflicted by her unnerving discovery at Adam’s house.
Not Break in the Kona Gale.) – 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, hostage. Also, Gerard Hirsch and Kamekona help Grover and Tani on a murder case involving masterpieces stolen by the Nazis during WWII and Tani makes a shocking discovery.
Ka hana a ka makua, o ka hana no ia a keiki (What Parents Will Do, Children Will Do) – McGarrett and Five-0 take on the mob when a former boss is killed and Junior’s friend Cammy Lin is on the run after witnessing the hit.