Five-0 investigates the death of a scuba diver who was killed with a gun found on the ocean floor that was used recently in another murder. Meanwhile, McGarrett prepares to propose to Catherine.moreless
A bomb squad is attacked and the culprit threatens to detonate additional explosive unless arsonist Jason Duclair is released from prison. Meanwhile, Adam returns from the hospital and Kono realizes they are being watched; and McGarrett prepares to take his relationship with Catherine to the next level.moreless
Season 6 begins with Five-0 investigating a centuries-old Oahu palace raid involving pirates, buried treasure and a killer who is using a stolen painting as a map. Meanwhile, Kono and Adam are threatened and tortured by Gabriel; and Danny shows concern for Steve regarding Catherine's return to the island.moreless
Season 5 ends with Five-0 learning that a stolen nuclear bomb is somewhere on the island and is about to be detonated. Meanwhile, McGarrett is stunned when Catherine returns to Hawaii; and Chin confronts Adam about his lingering connections to the Yakuza, on the eve of Adam and Kono's wedding.moreless
Steve and Catherine journey to Afghanistan to help a young boy whose family is responsible for saving Catherine's life many years ago.
After following up on a tip, Steve and Danny are trapped inside an abandoned building that is rigged to explode.
The daughter of a macadamia nut tycoon is murdered during Chin's high-school reunion. The investigation reveals that the victim was killed with a stiletto heel.
Five-0 investigate the abduction of a girl from her home which also resulted in her father being shot. Danny attempts to get his parents to reconcile and Jerry makes sense of a code he found on the bottom of McGarrett's champ box.moreless
Five-0 investigates three murders that appear related to a downed top-secret Chinese satellite. Captain Grover lets Clara accompany him on a ride-along.
An escaped convict out to prove his innocence kidnaps Steve and Danny. Grace punches out another student at school.
A serial killer at the heart of Five-0's investigation puts Chin's life in danger. While on the shores of Oahu, Danny and Grace come upon an odd puzzle box.
When someone tries to kill a Pearl Harbor veteran, Five-0 links evidence to a crime committed within the internment camps on Oahu during World War II.
With the President on the way to Oahu, Five-0 is tasked with the murder investigation of a secret service agent. Steve's Aunt Deb comes for a visit along with an eye opening secret.moreless
With national security in mind and at the behest of the Governor, McGarrett and Captain Grover set out to serve a warrant on a young computer hacker.
Five-0 is tasked with babysitting Mary's newly adopted baby, even as they investigate the murder of an undercover ATF agent.
Halloween and a shooting have Hawaii Five-0 looking for a man carrying out experiments and turning humans into zombie-like creatures.
Catherine's surveillance job turns deadly. In order to save Kono, Adam reflects on what his best move should be.
A runaway bride is the main suspect when a wedding crasher is murdered. Danny decides where his relationship with Gabby is headed.
To solve a double murder, Five-0 gets some help from a conspiracy theorist.
Five-0 assists a Texas Ranger in finding his missing daughter when they cross paths with him during a murder investigation. Adam and Kono run into problems and find themselves fighting for their lives.moreless
Steve and Wo Fat fight to escape from the attack on the maximum security unit. Catherine is taken hostage when Five-0 headquarters is seized. Five-0 goes behind the new SWAT Commander’s back to rescue Catherine. Kono and Adam find themselves exposed while hiding in Hong Kong.moreless
Five-0 is assigned by the CIA to find a missing federal prisoner after the plane he is being transported to Oahu on arrives without him, but instead has four dead bodies. After being set up for a murder, Kono finds herself on the outs again with the police force. Steve has another surprising encounter with Wo Fat. Danny reconnects with Gabrielle.moreless
Doris needs Steve's help on a clandestine mission to take back an incriminating microfiche. Kono is in jeopardy whilst getting closer to finding out Adam's secret.
Five-0 looks for kidnappers after they discover the body of the previous victim from ten years ago. Even though it might harm what she has going with Adam, Kono asks a favor of Catherine.
Things turn dangerous for a talk show host and her crew following Five-0 around when they run into Wo Fat.
Steve reflects back on his last mission in North Korea as he and Catherine recover the remains of fallen soldier.
Five-0 must determine who killed a member of a local company that is bringing sharks in closer to shore. Steve assists Kamekona in getting his helicopter license and this becomes a hot topic of discussion.moreless
A member of a local roller derby team falls to her death in front of Dog the Bounty Hunter, as he is arresting a fugitive just a few feet away. Catherine is sent in undercover as a new member of the derby team. Steve finds out that Catherine kept a secret from him involving his mother and questions whether he can trust her.moreless
During the pro-bowl weekend in Hawaii, the team catches a case investigating a murder and finds help from Arian Foster, running back for the Houston Texans.
The daughter of a murdered Lua master comes to Hawaii Five-0 for help. Steve decides to have a private investigator keep tabs on his mother.