Longtime faithful “Hawaii Five-O” fans recall every detail of the battles with Wo Fat, Gabriel Waincroft, and the totally despicable Marco who killed and put Danny's brother, Matt, in a barrel, despite the millions demanded in cash, back in Season 5. There had been some unforgettable foes who attempted to thwart the best crime-fighters ever known on the island throughout “Hawaii Five-O” history.

There has even been a robotic monster and many ghoulish Halloween fiends who did their best to take on the team.

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In this week's ninth episode for Season 8, “Make me kai” (Death at Sea), the villain that “Five-O” faces doesn't walk or carry an arsenal of guns, but comes as close as any to bringing the four of the five on the task force to death.

Not even a deadly hemorrhagic flu [VIDEO] destroys the “ohana” between the new or old members of this force, and the final 10 minutes are some of the most daring, caring, death-defying, and memorable moments in “Hawaii Five-O” annals. Lt. Commander McGarrett (Alex O'Loughlin) isn't the only Navy Seal hero [VIDEO] in this one.

Hardly alone

The day starts fairly typically at “Hawaii Five-O” headquarters, Danny (Scott Caan) and Steve are squabbling over serving gluten-free and healthy options on their restaurant menu, to which Danny says “they can go somewhere else” if patrons don't tolerate his family recipes. Junior has the best reply to the debate, responding that you only “here to learn and observe” rather than offer opinions.

When a socialite, Monique Sims (Alexandra Chando) is rescued alone and adrift from a life raft, the team traces the location to the yacht she left from, the Serenity, only to find that no one on board responds to McGarrett’s communication.

When they fly out for a deeper investigation, they discover a scene beyond gruesome, with 11 on board dead from the effects of “a biological agent,” leaving blood from nearly every orifice. It takes only nanoseconds for all the team to realize that they all been exposed to the same fate, and Steve insists that with no one can leave the ship under risk of exposing any other people, no matter the desire. Instead, they collect as much evidence as possible, including an actual tissue sample from a deceased woman, to send back on the helicopter, hoping the effort will lead to the identification of the agent and a cure.

Lou (Chi McBride) initially calls in Adam (Ian Anthony Dale) because Adam and Monique have known each other socially for a while, but Adam hasn't “been part of that scene” of social circles for a while, and doesn't recognize any of the victims. He and Lou soon find out that not only is there no available cure for this virus, but that finding one could take months, and this strain is very fast-acting.

The estimate is that the “Hawaii Five-O” team members on the ship have just eight hours to live, and very difficult hours before the end.

Not such a victim

Monique regains consciousness and relates to Adam and Lou that a man named Marko (William R Edwards) came on board from another ship while she was recovering from a headache, and began firing a gun. She says that she just ran for the life raft, wanting to spare her life. When Lou tells Steve about this Marko, it sends the team searching the ship for his body, and Steve finds him in the electrical room below. He doesn't seem to bear the evidence of the terrible flu. He looks like someone who has been shot, and that explains the fired flare that Danny had discovered earlier. A suitcase is found beside Marko, with vials of the virus, and one accidentally was broken, leaking enough to kill many. The CDC is at work to reach “Five-O” and a cure, but waiting and hoping are the only options.

Jerry (Jorge Garcia) does the work to “follow the money” and finds that Monique took a $500,000 payoff from offshore shell companies to bring Marko, also known as a Ukrainian bioweapons agent, Andreas Koslov. She obviously had agreed to help him transport the virus to Hawaii, and from there a horrific genocide could occur. There is a glimmer of hope when the team realizes that Marko/Koslov doesn't show signs of infection, meaning there is an antidote. Alas, none is found on board, and every member of “Hawaii Five-O” is now hurting from symptoms.

A standout feature from this episode is how every member of the team supports the other, from Junior (Beulah Koale) helping Noelani (Kimee Balmilero) to overcome her flying fears in the helicopter, to his moving words to Tani (Meaghan Rath) about not giving in to fear, reminding her that “you're still in the fight” and that their fate of death might be a “maybe,” but not a “probably.” Steve won’t talk any final goodbyes with Danny, either. The two share sips of some nice wine and Steve teases about now being the time Danny chooses to worry about “cooties.” Danny seems to decline fastest, and Steve nurtures him, much like he did through the building explosion in Season 5. They are committed as one to survival. A storm is brewing in the clouds.

Lou sets up a sting call to Monique from a would-be Koslov, seeing as she escaped before either his fate or the virus was exposed. He is committed to nailing Monique not only for information but for getting the antidote. She is cornered at the meeting location, thinking she is dropping off the cash and gets shot as she tries to run for it. Captain Grover makes it clear that her only choice is to cooperate or die. He is no Mr. Nice Guy this season.

Summoning united strength

Some of the most suspenseful “Hawaii Five-O” scenes ever fill the final minutes. Night falls amidst the storm, as time dwindles. A call comes that the helicopter has brought the antidote. Steve goes on deck through the downpour and sends a flare to guide the helicopter. Tani and Steve struggle to attach the cable to the ship. When Lou sends the case of antidote across the cable, the tension and swaying of the ship break the cable, and the life-saving red case falls to the water.

Steve could hardly walk minutes before, but now, he dives into the water. He goes for the case and gets swallowed by waves. Junior jumps in to save the man who is his mentor, and Tani does her part to drag them to safety on board. They collapse with exhaustion, but they are alive, and the injections of antidote are safe. Anyone watching had to be pumped with adrenaline.

Every member of “Hawaii Five-O” struggles with keeping it sedate and quiet, even in quarantine. Junior is doing crunches, and Tani has no trouble talking back to the boss during their chess match, concluding that “He's pretty good, but I'm just better.” As cameras fade, Danny and Steve go at it again, as Steve has a change of heart about their restaurant “waiting room.” Spirits are healing along with bodies.

Next week looks to carry over a little from this episode in the two-episode winter finale. Fans have no reason to lean back on the sofa just yet!