When threats turn deadly against a tour company that endangers the local shark population, Five-0 faces the difficult task of narrowing down the suspect list. Meanwhile, the team debates whether or not Kamekona will earn his helicopter license.

While apprehending his latest fugitive, Dog the Bounty Hunter is witness to a woman falling off a balcony to her death. Five-0’s trail leads them to discover that the victim lead a double life as a roller derby player. Unable to get any useful information about the victim from her teammates, Catherine is asked to go undercover as the team’s jammer. Doris comes home to find a burglar robbing her stash of sensitive information.

As the island prepares itself for the Pro Bowl, an executive from a California technology company is found dead after a tactical ops team building exercise. Unexpectedly, a star running back from the football game (Arian Foster) winds up helping Five-0 during the investigation.

Five-0 investigates the murder of a traditional Hawaiian fighting master. Meanwhile, McGarrett hires a private investigator to follow his mother.

A double amputee goes after the police officers responsible for his injuries — including McGarrett’s father.

The team is directed to investigate when a prostitute is murdered in a Congressman’s home, who is nowhere to be found. Danny has his own drama as the custody hearing regarding Grace goes to court.

Chin Ho becomes a victim of deception, after waking up behind bars with no memory as to how he got there.

Danny and McGarrett investigate the murder of an Oahu University professor whose body is found decomposing in a tub of acid and his boss, his teaching assistant and a student who he busted for cheating are all viable suspects.

After a carjack attempt on Steve and Catherine, they meet a boy whose father is missing and could be a grave danger.

An Aloha Girls camping trip with Grace turns deadly when an armed man takes McGarrett and a little girl hostage. Meanwhile, Adam introduces Kono to his dangerous brother who was recently released from prison.

Max and his crush (Rumer Willis) get put in harm’s way when a botched bank robbery leads the team to determine that the criminals had very unexpected motives. Meanwhile, Danny is stuck with the tough task of coming to the rescue of the most beautiful women in the world when a stalker goes after a Victoria’s Secret model.

McGarrett plays cat and mouse with a smart and seductive therapist he believes murdered her patient. Meanwhile, Catherine must hunt down one of Doris’s old targets who is now seeking revenge.

While the team investigates the murder of a young computer hacker, McGarrett tries to stage a long-needed reunion between his mother and his sister.

When Danny is forced to remain completely still while bomb technicians disarm a bomb that he has accidentally almost triggered, McGarrett distracts him by getting his partner to tell the story about his toughest and most emotional case from his days as a cop in New Jersey.

A grisly murder leads Five-0 to discover a ritualistic killing on Halloween, and the evidence suggests that the murderer will soon strike again.

The death of a polo player who literally loses his head is investigated. Meanwhile, McGarrett’s mother pays him an unexpected visit.

Steve and Danny take some time off to enjoy a little fishing only to find themselves stranded and facing pirates.

Steve goes to Cat for help finding his mother. When an art heist turns deadly, Five-0 turns to August March.

The team goes after Wo Fat and Delano for the death of an important person. Steve must resolve the issues between him and his “dead” mother, once he finds her alive and well.

Five-0 is in hot pursuit of a shooter who guns down one of their own, while another team member is forced to choose which of their kidnapped loved ones will live.

Just as McGarrett finally gets his hands on his arch nemesis Wo Fat in a special ops raid, he’s blindsided when he finds that the Japanese Yakuza is hot on their trail and wants them both dead.

Five-0 and the NCIS: Los Angeles task force team up in Hawaii when there’s a suspect on the loose who is threatening to release a deadly virus into the population. Series crossover part 2 is NCIS: Los Angeles S03E21.

A murder case hits close to home for Max when he is convinced that The Trashman, a serial killer with ties to his past, is on the loose. In order to convince Five-0 of his suspicions, Max reveals shocking information about his childhood.

When McGarrett’s sister is arrested for smuggling diamonds, he enlists the help of an ex-con to set up a sting.

Five-0 crosses paths with Tony Archer, a retired NYPD bomb expert who is now a private investigator on Oahu, when they investigate the death of famous talk radio DJ Bobby Raines.

Five-0 investigates the murder of a man dressed as a Hawaiian NaKoa warrior found in the jungle near the site of a historical war reenactment

When the team almost causes an international incident, Lt. Gov. Denning decides that one of them should be fired; Chin Ho faces the harrowing task of choosing a Valentine’s Day gift for Malia.

When Danno and his family are targeted by a vengeful dirty cop from Danno’s past, the team steps in to help.

Chin Ho shares news about Joe White that rocks McGarrett to his core; Danny is forced to play midwife when his ex goes into early labor.

When the Five-0 team discover that the murder of a High School girl was a professional hit, they must find out why she was targeted before they can find her killer.

On the eve of Chin Ho’s wedding to Malia, the Five-0’s investigation into a man left for dead in an abandoned WWII bunker crosses paths with Capt. Fryer’s case of a Jane Doe.

McGarrett and the Five-0 search for a busload of kidnapped school children as well as the people responsible.

McGarrett finds himself in need of the Five-0’s help when he goes to North Korea with Jenna Kaye to deliver a ransom to rebels who are holding her fiancé hostage. Meanwhile, the Five-0 investigate the murder of an investigative reporter who seems to have ties to Jenna.

When the Five-0 discover a John Doe in the trunk of a stolen car, they not only have to find a killer, but also need to figure out who the physically-altered victim was. Meanwhile, a homeless Danno is sleeping on McGarrett’s couch.

FIVE-0’s investigation into the suspicious plane crash and death of a customs agent takes an unexpected turn when it is revealed that the victim was dead before takeoff. Meanwhile, Danny finds himself the proud caretaker of an orphaned dog.

When the Five-0s investigate the murder of a young couple filming a spooky documentary about a traditional Hawaiian burial site, they are threatened by a drifter who puts a curse on Danny.

The FIVE-0’s investigation into the murder of a wealthy restaurant owner causes McGarrett to take part in a charity MMA fight to the finish. Meanwhile, NCIS Agent Kensi Blye lends her expertise to McGarrett and Lt. Commander White when they ask her to examine a video of McGarrett’s father.

The FIVE-0’s investigation into the murder of the state’s women’s volleyball coach leads them to find out more bad news about Kono, and Chin Ho reconnects with his former fiancée, Malia.

The Five-0 take to the beautiful waters off Hawaii to investigate the murder of a deep sea diver known for his valuable shipwreck finds.

At his mentor’s request, McGarrett persuades Max to redo the autopsy on a SEAL, thought to have committed suicide, in order to investigate his murder. Meanwhile, Chin Ho worries about Kono hanging out with a group of dirty ex-cops, including Frank Delano.