When a vacationing dad on a flight to Honolulu is kidnapped and force to parachute mid-flight, Danny, Tani and Junior track him through the jungle to discover that he may not be who he seems. Also, McGarrett is threatened with a secret from his past.
SO2 Junior Reigns and Jerry Ortega escort U.S. Air Force SSGT Kaliko Christopher coffin from Dover Delaware to Hawaii. Duke is forced to Retirement. Steve and Danno investigate Illegal Black Market sand.
Young Jerry witnessed a murder while at camp in 1982. He's telling this story to his friends while going back to the camp in the present day. He wants to search for the body before developers level the property. A woman watching a news story about a murder realizes that her daughter drew a picture of the crime scene three days earlier. Jerry's most likely site for the body is on the property line of Bo Bradley, who Jerry thinks is the Ax Man. McGarrett and Junior interview the girl. Katie. She says her friend Molly drew the picture. Noelani shows up to help hunt for ...
McGarrett crosses the line and is arrested while investigating the death of his former SEAL buddy, who died on an aircraft carrier, and the only survivor is a baby. Also, Adam returns to Oahu with some devastating news about his marriage.
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.
While a hurricane lashes Oahu, the Five-0 must house a federal prisoner with a history of escaping. Danny has houseguests during the storm, while an evacuation patrol puts Tani in a dangerous situation.
Tani and Junior go under cover at a gym to track down a deadly batch of steroids; Danny and MacGarrett work as bodyguards for Danny's high maintenance ex-mother-in-law, a famous romance novelist with whom he has never gotten along.
The team investigates the murder of a window washer and finds that the victim is actually a renowned street artist; Grover and Adam look into the murder of a gambler; Junior helps his father when they are reminded of his sisters death.
While Adam investigates the murder of an undercover FBI agent about to wed the daughter of a Yakuza leader, Noelani is held hostage and forced, along with her mentor Dr. Chu (Page Leong), to operate at gunpoint on a criminal.
Fugitive hacker Aaron Wright (Joey Lawrence) resurfaces to ask Five-0 for help when his co-workers at the NSA, which he has been working for, are all murdered. Also, Junior speaks at the parole hearing of the drunk driver who killed his sister.
Five-0 continues to hunt down escape criminal Aaron Wright before he can sell cyber-weapons to the highest bidder; the lives of McGarrett and the team members are put in danger when a visitor comes to headquarters to make amends.