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.

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

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.

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.

McGarrett and Grover must work together to protect national security after they are tasked by the Governor to serve a warrant to a young computer hacker.

The investigation of a murdered pool cleaner leads the Five-0 team to a possible terrorist cell of radicalized students plotting an attack on U.S. soil.

McGarrett and Catherine travel overseas to Afghanistan to stop the Taliban from harming a young boy whose family saved Catherine's life years ago.

While a Navy Seal is on a secret mission, his young daughter is kidnapped; Danny must find $18.5 million in order to save his brother.

On the fourth anniversary of his father's death, McGarrett meets a woman who helps him reopen the last unsolved case his dad worked on before he died.

A neurosurgeon is assassinated just before performing a surgery. The investigation uncovers the truth behind the disappearance of four reform school boys over 40 years ago. Meanwhile, McGarrett's beloved Mercury Marquis is stolen by an unlikely culprit.

When a journalist is killed, Five-0 must use his past reporting to hunt down a presumed dead Congolese warlord who is alive and well living on Oahu. Also, as Valentine's Day approaches, Danny overreacts when Grace's texts to a boy start accidently coming up on his cell phone.

When Grover’s oldest and closest friend tells him he witnessed his wife fall off a cliff to her death, Grover’s gut instinct tells him that this was no accident. Also, Danny and Dr. Shaw get trapped in an elevator with a dead body in need of processing.

When a performer is killed at a convention of Elvis impersonators and his body is stolen, Five-0 must track down the culprits who are after the hidden diamonds sewn into the victim’s costume. Also, Gabriel Waincroft returns to ask for Chin for help getting off the island.

When Kono goes on a solo outrigger trip around the Hawaiian islands in honor of her mother, she hits a patch of wild weather and must fight to stay alive. As Five-0 searches for Kono, they investigate a man busted for cooking meth who claims he received a threat on his son’s life if he didn’t continue making the drug.

Five-0 investigates when a wealthy recluse is found dead in a remote field with nearly one million dollars in counterfeit bills. Also, Adam is kidnapped by the Yakuza and forced to torture one of Gabriel’s men.

McGarrett’s first date with Lynn on a deserted island turns deadly when a mob boss hiding there hunts them down in order to keep his location a secret. Also, Chin, Kono and Grover must race against the game clock to locate the father of a high school football star who will be murdered by a local gambler if his son doesn’t throw the big game.

Five-0 goes back to school when a college professor is killed and Danny goes undercover as his replacement.

The brother of a promising local boxer is murdered, and the chief suspect is the outspoken reigning champion opponent from the mainland.

When a man is found left for dead drifting off the coast of Oahu, Five-0 uncovers a deadly slave trade operating aboard an illegal fishing vessel. Also, while Danny is out with his children, his car is stolen so he commandeers a bus to chase down the thieves.

A case from 15 years ago forces Grover to take his family on the run when a dangerous mob boss tracks him down to seek revenge.

Five-0 tries to save a kidnapped college student from a dangerous vigilante. Meanwhile, Max, Kamekona and Flippa fight to survive after being shipwrecked.

On Halloween, Five-0 investigates the murder of a medium with a checkered past who was apparently scared to death by a poltergeist. Also, Kono and Adam are kidnapped by what appears to be a death cult.

While McGarrett and Danno celebrate Valentine's Day with their girlfriends, the rest of Five-0 investigates the murder of a man taking a class on how to land women.