Hawaii Five-O - Season 4 (1971)

A cagey professor and the syndicate team up on a deadly caper. About $750,000 in traveler checks are stolen in Denver. A planeload of criminals posing as academics board a charter flight to Honolulu, with each given $7,500 in traveler checks to spend. A hit man ensures a woman employee of the Honolulu office of the traveler check company can't get the serial numbers of the hot checks circulated. McGarrett calls the caper a "jigsaw puzzle." The question is whether he can solve it in time.

Two hippies, panhandling for money, decide to approach a tourist. The first hippie, a young woman, is rebuffed. However, the tourist comes on to the second, male hippie. The hippie freaks out and hits the tourist on the head with a board, taking the man's wallet in the process. The wallet contains a key to an airport locker, which contains a briefcase full of money. It turns out the tourist is an embezzler who will do anything to get the money back.

A mentally disturbed former soldier buys a new rifle and ammunition after a sales clerk fails to check him out. The soldier even signs his name as "George C. Patton." He then holes up in a spot on Diamond Head and shoots out the tires of a motorist's car and proceeds to shoot two police officers, one fatally. McGarrett coordinates the police response. The more McGarrett finds out, the worse it gets. It turns out the sniper has a weird relationship with his mother. The mother, in turn, denies the former soldier is her son. Time is running out and Five-O must prepare to...

A shipping company which runs lots of valuable cargo through the islands is cherry-picking the most valuable items, taking them out of the shipments, and selling them on the black market. They also have a habit of killing anyone who gets too close to their operation. Their fatal mistake is stealing a quantity of medicine which is the only thing that can save a toy manufacturer's critically-ill wife. When the emergency re-order arrives too late, the husband -- who has been cooperating with Five-O -- goes off on his own to seek vengeance.

A gang, led by the vicious Hawkins, is executing a plot to steal $6 million. The group includes a bank employee and an alienated, long-time employee of a trucking company. The plan results in multiple deaths. Dan Williams leads the Five-O investigation because McGarrett is having to testify at a trial on the "Big Island."

The wife of a wealthy doctor is shot to death. The physician seems to have a tight alibi while clues point to another man. But the more Five-O probes, the more the obvious turns out not to be. The suspect is arrested while trying to fence the dead woman's jewelry. But he was dying and had little motive to kill the woman. McGarrett & Co. need to dig deeper to find the truth.

McGarrett gets a telephone call upon arriving at work. The caller says he intends to kill someone. The caller has also sent the lawman a key that will tell McGarrett the identity of the target. Danny and Kono have received other clues at their homes, one of which is a photograph of Chin Ho's garage. The clues are a mixed bag, including several false leads. The caller continues to taunt McGarrett, finally revealing that the intended victim is the Governor.

French McCoy, thug for a Miami mobster, turns up dead (stabbed in the chest) and mutilated (one of his pinkie fingers cut off). The mobster, known as "Big Uncle," was looking to move into Hawaii. One of four Hawaiian mobsters is responsible. McGarrett must figure out which one before a gangland war erupts.

Willy Stone, a punch-drunk former boxer, attacks a young fighter for no apparent reason, breaking the younger man's hands. Edmonds, a Detroit hood, has invested much in the young boxer and is enraged when he finds out the boxer can never fight again. Five-O seeks to find Willy before Edmonds can extract his revenge. Meanwhile, Edmonds has summoned a hit man from the Mainland to kill Willy.

Someone calling himself "Kaili" (the Hawaiian god of battle) wages his own personal war against polluters. At first the pranks are bad but not dangerous, like climbing a ladder to the top of a huge chimney with a 125-pound ceremonial shield and capping the chimney (thus blowing out the furnace inside and chasing everyone out of the factory). However, Kaili's actions get steadily more violent. After blasting a crop-dusting plane with a shotgun (he pulls the pilot to safety), Kaili types up a list of the five worst polluters in Hawaii and entitles it "Kaili Death List."...

When famed bank robber Lewis Avery Filer, whom McGarrett put away a year and a half ago, learns that a fellow con about to be released plans to resume his career as a drug dealer, he decides to get out on his own and infiltrate the drug gang. Filer plans to tail the drug dealer and relieve him of the $4 million he's received for cocaine shipments, through use of trickery and gadgetry. McGarrett tries to outwit Filer once again and recover the money before Filer can flee with it.

A young woman goes onto a balcony in what is thought to be a suicide attempt. However, it is all a plot to lure her fiancée out into the open to kill him and prevent him from testifying against a mobster. After he has been liquidated, McGarrett must now try to prevent the woman from becoming the gang's next victim.

McGarrett is found in an upside-down car containing a dead crime lord and a briefcase with thousands of dollars. Each step of the frame is perfect and unbreakable. McGarrett figures only man can be responsible -- Wo Fat. Indeed, the Chinese intelligence operative has just arrived in Hawaii. It turns out Wo Fat arranged for a man to undergo many plastic surgery operations to look exactly like McGarrett. The man is caught and fatally wounded as he tries to withdraw money from a Swiss bank. Before he dies, the double says, "Wo Fat bought my soul for 90 seconds."

Steve returns to Hawaii after discovering the man who was made to look like him in Switzerland. Steve meets with Jonathan Kaye and some other people to find out why Steve was framed. They know Wo Fat is behind it. Steve learns that the only anomaly was their tracking station went out for a few seconds. Steve wonders if that is what Wo Fat is working on because they know that all this about Wo Fat trying to get 90 seconds for something and with their tracking system done for 90 seconds; what could happen? They look at everyone who could have done it, Steve thinks they ...

A young woman is savagely beaten and raped outside a bar. The prime suspect is a bald headed soldier, with whom she was seen arguing inside the bar. The jury eventually convicts him based on the eyewitness testimony of a young mechanic who was at the bar that night. However, when his medical report comes back McGarrett begins to have doubts about whether or not he did it.

A reclusive, Howard Hughes-type billionaire is implicated in the murder of one of his associates. The businessman abducts McGarrett, who was on his way to the scene of the murder. The businessman is afraid of germs and has elaborate decontamination procedures on his yacht. The businessman tells McGarrett that he is innocent and being framed. The businessman wants to sell off his various companies to concentrate on developing a "steam car" that will run on natural gas and have few emissions. The business associates opposed the move and the leading opponent is the one ...

At a birthday party, the guest of honor suddenly suffocates after getting a card saying this is his last birthday. The dead man is one of three partners in a shady real estate business with a reputation for swindling its customers. Five-O's investigation intensifies after a second partner gets a similar threat. When the second partner turns up dead, McGarrett knows he is running out of time to solve the case.

A convicted murderer escapes prison. He has been threatening a woman, spurring McGarrett to arrive at the woman's home with police officers. As the lawman arrives, the convict calls, telling the woman he will kill her by nightfall. While McGarrett guards the woman, he also probes to find out more about the circumstances that led to the man's conviction. It's clear that McGarrett believes there's more to the case than she has been telling.

Three seemingly ordinary people are recruited to make a hit on a mob boss from Chicago visiting Hawaii. The hit is done with precision. The killers are equipped with firearms with plastic coverings that prevent shell casings from being left for evidence, for example. Also, the three participants, in effect, provide alibis for each other. Five-O initially thinks this is a professional hit until its probe begins to uncover the truth. McGarrett & Co. must figure out why these three people were so desperate they could be blackmailed into performing a murder. Second, ...

The U.S. Navy cooperated in the filming of this story about a shipboard heroin ring, lending the Destroyer U.S.S. Whipple and having real-life Admiral Joseph McGittrick play a substantial role as the admiral in charge of the Navy's substance-abuse recovery program. With McGarrett in uniform to supervise, Danno goes undercover as a medic treating an addict and trying to get him to produce his supplier's name with an amnesty promise. Several sailors also have speaking roles.

A disturbed ex-GI who was dishonorably discharged and then tried to re-enlist under a false name takes revenge at the Military by murdering officer's wives who fly to Hawaii expecting to meet their husbands on R&R from Vietnam.