Five-0 investigate the murder of a window washer and find that the victim is actually a renowned street artist who may have a politically motivated bounty on his head. Also, Grover and Adam look into the murder of a gambler, and Junior helps his father when they are reminded of his sister’s death.

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.

Junior is torn between his duties as a member of Five-0 and his feelings for his former girlfriend when her new love, the father of her son, is one of the culprits in a bank-heist-turned-homicide.

When the top salesperson for a beauty company/pyramid scheme is murdered, Five-0 sifts through a long list of possible suspects who would want her dead. Also, Adam befriends a homeless man estranged from his family.

As a dangerous hurricane hits Oahu, Five-0 is tasked with protecting El Diablo, a captured serial killer who is being hunted by an assassin. Also, Tani’s civilian safety check during the storm turns deadly and Rachel and Charlie evacuate to Danny’s house, where the ex-spouses reminisce.

While investigating Flippa’s friend’s murder, McGarrett and Grover uncover a deadly plan by an extremist group on the Island. Also, Grover has an emotional reaction to the case.

Adam, Junior and Tani travel to the bottom of the Pacific Ocean when a murder takes place in a remote underwater lab, and the killer may still be on board

MacGarrett and Five-0 support Danny and Rachel by determining what happened when gets into a life-threatening car accident and lands in critical condition. Also, Tani helps Koa when his rehab patient goes missing.

Steve and Catherine are still reeling from the murder of one of their ohana and, along with Danny, Junior and some old friends, Harry Langford and Wade Gutches, hunt down the killer. Also, Tani and Grover investigate when a bag of human bones, discovered inside an abandoned storage locker, goes missing.