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
Amember of a local roller derby teamfalls toher death in front ofDog the Bounty Hunter, as hewas 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.
A man who was injured years ago begins taking revenge on the police officers who caused his injuries, including Steve whose father was one of the officers responsible for his maiming.
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.moreless
Chin is kidnapped and taken to the Halawa Prison, where he is dressed as an inmate. He must find a way out before his identity is revealed.
The fate of humanity is on the line as Walter plans to make the ultimate sacrifice to stop the Observers before they were ever created.
To penetrate the Observers' headquarters and rescue Michael, their only hope for victory, Olivia must use her abilities and meet with some old friends.
While Walter tries to learn more about the mysterious Donald after Michael's revelation, Windmark undertakes his own quest for knowledge.
The team joins forces with Nina to recover a key piece of the plan that Walter created to defeat the Observers.
When Steve arrests a man who attempted to car jack him, he meets a young boy at the station, who peaks his interest. The boy's father is missing and Steve decides to help him, being concerned that the father may be in real trouble.moreless
While Olivia and a recently-recovered Peter investigate a mysterious signal coming from a forest, Walter uses LSD to try and recall his memories of his plan to defeat the Observers.
A camping trip with Grace doesn't turn out as planned when an armed man takes Steve and a little girl hostage. Kono meets Adam's dodgy brother just out of prison.
Peter reaps the consequences of spying on an Observer leader. Meanwhile Olivia's search for another tape leads her to a woman who seems to be able to divine the future.
While Danny gets assigned to protect a Victoria's Secret model, Max and Sabrina find themselves in danger when a bank robbery goes awry.
When a therapist's patient is murdered, Steve finds evidence that the therapist may be involved. Catherine finds herself mixed up in Doris' past, when a former target is looking for payback.
Steve attempts to arrange a reunion between his mother and sister. When a young computer hacker is murdered Hawaii Five-0 steps in.
The fight against the Observers intensifies and a Fringe team member plans an attack on his own.
Forced to remain completely immobile, Danny tells Steve about his toughest case when he was a cop in New Jersey while bomb techs try to disarm a bomb he inadvertently triggered.
The Fringe team investigates a pocket reality occupying an apartment building, and Peter learns that he has the power to stop the Observers.
Peter takes extreme measures when the team learns of a way to stop the Observers from changing Earth's atmosphere and wiping out humanity.