The night was especially dark as U.S. Coast Guard seaman John Cullen patrolled the sand dunes of Amagansett, New York, shortly after midnight on June 13, 1942. Regulations in effect after the United States entered World War II six months earlier had already imposed blackouts on the village nestled in the Hamptons, and the thick fog that blanketed the east end of Long Island made it even more difficult for Cullen to see.

The 21-year-old “sand pounder” listened to the Atlantic Ocean lap up on the shore when the figures of four suspicious men suddenly crystallized in the fog. Of course, any men on the beach in violation of the nighttime curfew were by definition suspicious, but something was particularly odd about these men who claimed to be local fishermen who had run aground.

The group’s leader, who gave his name as George John Davis, didn’t seem dressed for the part in his fedora, red zippered sweater and tennis shoes. The self-proclaimed fisherman then refused to return to the nearby Coast Guard station with Cullen. Perhaps realizing that there was nothing more he could possibly do to arouse suspicion, the ringleader blurted, “Look, I wouldn’t want to kill you. You don’t know what this is all about.” The faux fisherman pulled out a wad of bills from a tobacco pouch lodged in a pocket of his wet pants and said, “Forget about this, and I will give you some money and you can have a good time.”

Cullen heard one of the men speaking in a foreign language before $260 was shoved in his hands. Unarmed and outnumbered, Cullen used his discretion and began to return to the Coast Guard station a half-mile away. Once out of eyeshot in the fog, his gait quickly sped up into a sprint.

Cullen burst into the station, awoke his colleagues and pronounced, “There are Germans on the beach!” The Coast Guardsman had indeed encountered four Nazis, but he wasn’t aware that they had just come ashore in a rubber boat laden with explosives, cash and intentions of sabotage.

Even before the United States entered World War II, German military intelligence had developed a plan codenamed Operation Pastorius—in honor of Franz Daniel Pastorius, who in 1683 had launched the first permanent German-American settlement in Germantown, Pennsylvania, now part of Philadelphia—to secretly infiltrate the East Coast and sabotage American war efforts. Walter Kappe, a German army lieutenant who had spent several years in the United States, recruited the saboteurs, all of whom spoke fluent English and had lived in the United States for a time.

The recruits attended a “sabotage camp” at an estate outside Berlin where they learned to make bombs, incendiary devices and even timers constructed from “just dried peas, lumps of sugar and razor blades,” according to a report by British intelligence agency MI5. They visited factories and transportation facilities to learn about infrastructure vulnerabilities.

The saboteurs were tasked with disseminating anti-war propaganda and destroying American bridges, railroads, waterworks, factories, reservoirs and power plants. According to MI5, they were also “instructed to carry out small acts of terrorism such as the placing of incendiary bombs in suitcases left in luggage depots and in Jewish-owned shops.” However, they were told to avoid causing deaths or injuries “as this would not benefit Germany.”

The first cell of four Nazi saboteurs departed a German submarine base at Lorient, France on May 26, 1942. The next four-man group left two days later. The saboteurs were given $175,200 in United States currency sewn into the lining of duffel bags, enough to finance two years of operations, as well as handkerchiefs with the names of Nazi sympathizers in America written in invisible ink.

Operation Pastorius experienced a rocky start when the U-boat carrying the saboteurs to Amagansett ran aground on a sandbar 100 yards off the Long Island coast. Unnerved by their unexpected encounter with Cullen, the saboteur cell led by 39-year-old George John Dasch, the Nazi who had given the alias of George John Davis to Cullen, hastily changed into shabby fishermen’s clothing hidden in duffel bags, buried its equipment in the sand for retrieval later and disappeared into the scrub beyond the beach.

The U-boat managed to free itself before dawn’s first light appeared. Cullen returned to the scene of his confrontation and discovered a pack of German cigarettes and footprints that led to the spot where the Nazis had buried their stash. The Coast Guard discovered a satchel of cash, two trench shovels and wooden boxes sealed in wax containing fuses, timers and dynamite. As a manhunt ensued, the four Nazis departed Amagansett on the 6:59 a.m. Long Island Rail Road train to New York City.

Perhaps it had been his plan all along to subvert the operation in order to be an American hero or perhaps he felt the operation’s cover had been blown in mere minutes after wading ashore, but the day after arriving in the United States, Dasch contacted the New York office of the Federal Bureau of Investigation (FBI) using the code name “Pastorius” to say he had arrived from Germany and would contact FBI Headquarters in a matter of days. On June 18, Dasch checked into the Mayflower Hotel in Washington, D.C., and contacted the FBI, which took him into custody. The next day, the other members of Dasch’s cell were arrested in New York.

By this time, the second cell that had departed France in a submarine had already infiltrated the country, coming ashore at Ponte Vedra, Florida, wearing nothing more than swimming trunks and marine hats emblazoned with Nazi swastikas. After making its way north to Jacksonville, the cell continued on to Cincinnati by train before splitting up to Chicago and New York.

Based on the information given by Dasch and his colleague Ernst Burger, the two Nazis in New York were taken into custody on June 23, and the last two saboteurs were arrested in Chicago on June 27. The Nazis had failed to carry out any attacks and did little more than spend $612 for clothes, meals, hotels and travel in addition to the $260 bribe given to Cullen, for which the Nazis had gotten a poor return on their investment.

President Franklin D. Roosevelt appointed a special military tribunal with seven U.S. Army officers to preside over a trial of the eight men held inside the U.S. Department of Justice Building in Washington, D.C. Attorney General Francis Biddle led the prosecution, while the defense team included the son of U.S. Supreme Court Chief Justice Harlan Stone.

The trial began on July 8, less than a month after the Nazis came ashore. Several weeks later, all eight saboteurs were found guilty and condemned to death. While Biddle and FBI Director J. Edgar Hoover successfully lobbied Roosevelt to spare the lives of Dasch and Burger due to their cooperation, the other six were executed by electric chair on August 8. In April 1948, President Harry Truman granted clemency to Dasch and Burger and deported them to West Germany.