Miss Diketon was the lovestruck personal assistant to Louis Strago (Jack Palance), a wine tycoon. The two of them were THRUSH agents. Strago recruited Nazi scientist Dr. Von Kronen (Ludwig Donath) to help him redirect the Gulf Stream north to turn Greenland into a tropical paradise. He felt by doing this, he could and THRUSH could rule the world.
Our first look at Miss Diketon is when Strago is receiving a rubdown from her at his winery in Sicily. She is dressed in a very short minidress, and Strago complains about her heavy breathing, followed by her skirt being too tight, the lenght too short, and the neckline too low. He reminds her that it is in violation of the THRUSH uniform code.
When U.N.C.L.E. agents are sent to Sicily to take out Strago, they are ambushed by some of Strago's men. Illya Kuryakin (David McCallum) escapes, but Napoleon Solo (Robert Vaughn) gets cornered inside a pizzeria, which is blown to pieces by a grenade.Luger (Vincent Beck), one of Strago's men reports back to him that he suspects Napoleon is dead, but Illya is still at large. Displeased by the news, Strago sends for Miss Diketon, who unzips the side of her skirt, whips out a dagger from a holster strapped to her sexy thigh, and hurls it at Luger. Later we see that Napoleon has been taken in by the pizzeria's owner, a beautiful young woman named Pia Monteri (Leticia Roman).
Illya steals a THRUSH uniform and breaks into the winery, where he discovers that Strago is filling wine bottles with super-heavy magnetic water, which will be used to divert the Gulf Stream. While posing as a worker, Illya comes under Miss Diketon's radar.
Pia's grandmother discovered Illya under her bed hiding, and used her shotgun to threaten to call a priest and make an honest woman of her granddaughter. Illya contacts Napoleon to come save him, and he arrives just in time.
Pia and her grandmother fly to Chicago and round up her great uncles, the Stiletto brothers who are notorious Prohibition-era Chicago gangsters.
Meanwhile, Strago returns to his home in Chicago. Illya poses as a longshoreman, and snoops around Strago's warehouse. He sets off random explosions and is spotted by Miss Diketon, who alerts Strago to his presence. We find that the Stilleto brothers are associates of Strago, and convinces them to go after Illya. Napoleon rescues Illya, but is captured by the Stilletos himself, and is whisked off to an impromptu wedding ceremony.
Illya is left to deal with Miss Diketon, who captures him. After tying him up, she tells him that she is "just going to love you to death". However, she tortures him with an electrified cattle prod while carrying on a cheerful monologue.
In the meantime, Strago crashes Napoleon's wedding, and kidnaps Napoleon and Pia. However, Napoleon is able to escape. back at U.N.C.L.E. headquarters, Napoleon is filled in on the latest developments. Strago has moved his main base of operations on his privately owned island in the Caribbean. They decide to mount an airstrike and reduce the island to rubble withing the next sixteen hours. Napoleon protests, saying that Strago is holding Illya and Pia as prisoners on the island. Therefore, he is given a chance to try to rescue them before the island is bombed.
At Strago's island compound, Miss Diketon brings Illya to see Strago. He said he would be kept alive until a top level U.N.C.L.E. representative can arrive at the island. On a tour, Illya is shown a giant reflecting disk powered by a hundred thousand vibrating tuning forks, which can demolish anything in its path. Strago aims the reflecting weapon at an approaching boat, that is piloted by Napoleon, and forces Illya to watch while he blows it to pieces.While this demonstration takes place, Miss Diketon is left to watch over Pia in the conference room. Pia and Miss Diketon begin to size each other up, and Pia whips out a stolen letter opener. Miss Diketon brandishes her knife, they roll around together on the conference table, and a good old-fashioned catfight ensues.
Pia gets the upper hand and makes a break for it. She is caught by a furious Strago, who returns her to her prison cell, then chews out Miss Diketon for her failings. Strago tells her that he intends to have her transferred out of his department.
Napoleon is fished out of the ocean by the Stilleto brothers, who've come to rescue their grandniece from Strago. They hijack a TRHUSH boat, change into THRUSH uniforms, and invade the island.
Having been spurned by Strago, Miss Diketon decides to switch her allegiance to Team Illya. She visits him in his prison cell, where Pia has been trying in vain to flirt with him. Miss Diketon makes Illya an offer, that if he helps her kill Strago, she will help him escape in time to stop the missle launch. Suspicious and baffled by the random offer, Illya agrees.
Thaler, he head of THRUSH arrives and begins planning a public execution of Illya prior to the missle launch. Prior to the killing, Strago throws a party for Thaler, complete with dancing girls, fruity drinks served with coconuts, and flowered leis. During the party Strago informs Thaler of his intentions of transferring Miss Diketon out of his department due to her moral corruption. However, Thaler suggests to just kill her and save everyone the paperwork.
Miss Diketon rescues Illya from his cell. After killing Dr. Von Kronen and a THRUSH guard, Illya changes into a THRUSH uniform and heads off after Strago with Miss Diketon. They are met up with Napoleon and the Stiletto brothers. They formulate a plan to have Napoleon take out the tuning fork, while Illya and Miss Diketon will stop the missle launch and rescue Pia and kill Strago. Meanwhile the Stiletto brothers will stand around shooting anything that moves.
While trying to rescue Pia, they discover that she has been moved from the prison cell into his suite. Miss Diketon bursts into Strago's quarters, intent on killing him. Instead, Strago knocks her out, then heads off to launch the missles. The injured Miss Diketon tells Pia where she can find her uncles, then charges after Strago.
Illya tries to find some way to sabotage the missle launch. He is able to kill Thaler with a pressurized blast from the missle chamber. The lair rapidly floods with water, and he swims to safety after fighting with more guards.
Napoleon battles with Strago at the reflecting disk controls. Miss Diketon joins the fight and is shot and mortally wounded by Strago. Before dying, she triumphantly watches as Napoleon kills Strago. She dies in the arms of Napoleon.
With Strago dead and the missle launch stopped, Napoleon and Illya get off the island before U.N.C.L.E.'s bombers arrive to destroy everything.
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