Here’s what you’ll learn when you read this story:

• As Fidel Castro aligned Cuba with Soviet forces in the early 1960s, the CIA huddled together to dream up the best way of toppling him and his Communist regime.
• Operatives pitched everything from poisoning his cigars to spreading fungus in his scuba diving suit to slipping something lethal into the milkshake he ordered on repeat.
• Fortunately for Castro, even the assassination attempts that seemed the most viable only managed to come close—but no cigar.

Poisoned cigars. Exploding seashells. Toxic exes. When it came to assassinating Fidel Castro, the CIA had no shortage of bizarre ideas on how to make him disappear. But “El Comandante” managed to elude every attempt on his life.

Sandwiched between the spectacularly failed Bay of Pigs invasion and the Cuban Missile Crisis that nearly set off a nuclear war, Project Mongoose was the codename for the many covert (and not-so-covert) attempts by American intelligence operatives to eliminate Castro. In 1959, the young revolutionary overthrew a dictator only to become one himself, and Cuba soon became aligned with the Soviet Union as the Red Scare loomed stateside. Anxiety escalated to paranoia, and as Castro kicked back with a cigar after U.S.-backed forces surrendered at the Bay of Pigs, CIA operatives clustered behind locked doors to conspire against him.

Cuba became a lightning rod for President John F. Kennedy’s foreign-policy makers as they struggled to deal with the spread of Soviet communism, a possible nuclear threat, and the threat of East Berlin being overrun. In 1961, tensions with Khrushchev only rose in the aftermath of a disastrous meeting with Kennedy that resolved nothing. Strategic planners assumed that the Soviets would invade East Berlin to retaliate if the U.S. made a move in Cuba, or vice versa. Fear of all-out nuclear war forced the CIA to stay deep undercover as they tried to figure out what to do about Castro, and in November of 1961, Operation Mongoose flashed its claws.

Backed by the U.S. Information Agency (in cooperation with the Department of Justice and headed by Air Force General Edward Lansdale), when Operation Mongoose was unleashed, it had no shortage of unorthodox ideas. A now-declassified document—released by the CIA in phases from 1989 through the early aughts—details proposed ways of dealing with Castro, which ranged from elaborate simulated disasters to suggestions like: “We could blow up a U.S. ship in Guantanamo Bay and blame Cuba.”

After hitting Cuba with the trade embargo that’s still in effect today, the U.S. made sabotage its top priority. This included anything from bombs and assassin squads to inciting riots and clogging the tanks of government vehicles with sugar. Threats scrawled on pieces of paper were wrapped around rocks meant to smash officials’ windows.

As Castro continued to live his best life, the plans for attacking him became less and less conventional. Castro was a known cigar aficionado, so poisoning a box of his preferred cigars with botulinum toxin seemed like a foolproof way to snuff him out. Yet somehow the poisoned cigars were either lost or intercepted, and none ever made it to his lips.

Eventually, in an unholy union, the CIA also turned to the mafia, recruiting notorious gambler John “Handsome Johnny” Roselli to round up mob contacts for the aptly named “Family Jewels” operation. Roselli reached out to kingpin Salvatore “Sam” Giancana and Santo Trafficante, both high up on the FBI’s Most Wanted List, and the gangsters’ financial interests in Cuba soon had them working hand-in-hand with the government. The gangsters pitched options such as lobbing a grenade at Castro during a baseball game (which never happened) and poisoning Castro’s favorite milkshake at the Havana Libre hotel (which failed when the poison capsule froze to the coils of the hotel’s freezer).

Additionally, the mafiosi floated the idea of of rigging a seashell with explosives and planting it underwater in the Caribbean fishing locale Castro frequented, but they couldn’t find a shell large enough to hide the explosives in. There was also talk of spreading infectious fungus on the inside of Castro’s wetsuit to give him fungal mycetoma (which causes unsightly blobs to grow under the skin) and poisoning his breathing apparatus with tuberculosis bacteria.

And that wasn’t the only biological warfare tactic tested they considered. Especially controversial were experiments with infected ticks intended to spread Lyme disease in Cuba, which may or may not have contributed to an outbreak of Lyme on the home front. And when all else failed, the CIA pursued a more personal way of getting at their target. Castro had a reputation as a womanizer, but contacting a scorned ex didn’t have the intended effect either, as she found herself unable to slip the poisoned pills she’d been given into his drink.

The frustrated intelligence agents decided that if they couldn’t assassinate Castro, they could at least publicly humiliate him. Thallium salts in his shoes could have make his iconic beard fall out when he traveled internationally, but that plan collapsed when Castro cancelled the trip. Next, American spies planned to spray radio equipment with aerosolized LSD right before Castro was to give an important radio address, but El Comandante never took that trip, either.

In the end, Operation Mongoose involved $50 million a year and at least 600 operatives, yet Castro spent years laughing in the face of the CIA as their plots either tanked or were never realized. He was seemingly untouchable until his death in 2016 at the age of 90, when natural causes did what hundreds of CIA operatives and the mafia were unable to accomplish for decades, even with armloads of poison and ammunition at their disposal.