Persons with foreign names, especially German names, were under enormous suspicion. Under equal suspicion was almost anyone caught strolling past a military post or factory that turned out munitions tagged for Europe.

Secret wireless transmitters; Germanic-appearing characters with fierce moustaches (cloaked in black) dashing about in touring cars in thc dead of night; "spies" who were allegedly poisoning wells or sowing germs like sunflower seeds -- all seemed credible and ominous in those days.

Much of this was hysteria. On the other hand, there was very real cause for concern over sabotage, though not for total panic. This concern could reasonably have commenced with the arrival of the new German Ambassador to Washington, sinister-appearing Count Johann Von Bernstorff, in August 1914, after war had broken out in Europe.

Von Bernstorff was accompanied by an unusual staff, spearheaded by Dr. Heinrich Albert, blandly listed as a "commercial attache." Also with him were: Dr. Bernhard Dernberg, propagandist; Capt. Franz von Papen, military attache; Capt. Karl Boy-Ed, naval attache; and a far more shadowy and little-known individual, Wolf von Igel (whose very name seemed to connote intrigue and conspiracy).

The most provocative aspect of this diplomatic "team" from Berlin was its "spending money" -- a whopping $150 million. And this was just a starter.

Like any consular group, the Germans were expected to try to influence public opinion in favor of their homeland.

However, von Bernstorff and company went considerably farther. As it turned out, the Count had brought with him as fine a viper's nest as ever writhed in Washington's embassy row.

In a very few weeks, on January 1, 1915, the first reptile eggs hatchedm -- incendiary fire in the Roebling Steel foundry in Trenton, N.J. It was followed, in rather quick succession, by fires and explosions in other plants and factories dealing in war contracts for the Allies. The next month there was a comic-opera climax in the clumsy attempt by a German army officer, Werner Horn, to blow up a railroad bridge linking Vanceboro, Maine, with Canada.

There could be very little doubt that Albert, Dernberg, von Papen, Boy-Ed and von Igel were bent on activities which were most undiplomatic. Theirs had turned into something other than a goodwill mission.

When von Papen was not roistering at Washington and New York night spots, he was busy in a "front" office at 60 Wall Street, in lower Manhattan, issuing false passports for German agents to England and France, and paying off a multitude of organizations and individuals spreading anti-Allied sentiment. There were many takers.

To the masterminds in Berlin -- primarily Col. Walther Nicolai, director of the Nachrichten Abteilung, the intelligence headquarters, centered in Berlin -- inflaming public imagination in the United States still wasn't enough. Dr. Albert, in a ridiculous charade of bungling, had allowed a U.S. Secret Service agent to snatch (in a New York elevated train) a briefcase containing incriminating literature about the Germans' activities. It involved not only Albert, Boy-Ed and von Papem but Dr. Constantin Theodor Dumba, the Austro-Hungarian Ambassador and an American, George Sylvester Viereck, poet, propagandist and publisher of the militantly pro-German newspaper Vaterland.

The documents chronicled sabotage and projected activities, including an ambitious program to place fire bombs on Allied ships; wreck the Welland Canal, which bypasses Niagara Falls; and Wreak general chaos along the Canadian border.

That did it Albert, Boy-Ed, von Papen and Dumba were sent packing. Von Bernstorff miraculously weathered the storm. But Colonel Nicoiai knew that it was now time to rush in a reserve professional sabotage tean. It consisted of one man -- the suave, aristocratic army reservist, Capt Franz von Rintelen.

"Munitions," von Rinelen confided to his friends at the Hotel Adlon in Berlin, "munitions ,my job -- what I can't buy I'll blow up , kaput schlagen!"

Buying was an empty boast. Already, the Allies' investment in U.S.-made materiel of war was approaching an annual $3 billion. Blowing up munitions was more within the realm of practicability.

Von Rintelen perfected the "pencil" bomb, a devilishly simple incendiary device which ignited cargoes when ships were far at sea. It was estimated later that he alone had destroyed $10 million worth of cargo on 36 ships.

In the United States less than three months, von Rintelen had worked fast. A spurious telegram, concocted by Scotland Yard, lured him on his way back to Germany. He was removed from a neutral ship at Falmouth, arrested and eventually returned to the United States for trial and imprisonment in the Federal Penitentiary in Atlanta.

Before this supreme trickster had himself been tricked however, he was to recall strolling along the New Jersey waterfront one day and noting the intense activity at a mile-long pier jutting out from the settlement of Communipaw, opposite the Statue of Liberty. This was Black Tom Pier, resting partly on diminutive Black Tom Island, and containing a complex of warehouses and the tracks of the Lehigh Valley Railroad. The name "Black Tom" was said to have originated from a swarthy-skinned fisherman, once the island's sole inhabitant.

Cargo ships, lighters, barges and tugs -- many loaded with explosives -- buzzed around it like so many giant bees about a honeycomb. Captain Rintelen stood there staring at this spectacle of feverish activity, like a fox having come upon a henhouse.

"What an ideal pier to destroy," he was to admit reflecting.

The "Dark Invader," as he liked to think of himself, had, however, finished his invasion. But his wish was to be granted by others who were to rub the magic lamp of sudden and all-consuming destruction the war's greatest single act of sabotage.

JULY 29, 1916, was a sultry Saturday night. The longshoremen had gone home. The switching engines, their fires cooling, stood silent on the sidings of Black Tom Pier. In nearly 100 freight cars awaiting unloading, in barges and in already half-carged freighters, was a bumper crop, even by Black Tom's standards, of somewhere between 2 and 4 million pounds of explosives. There were all types, from small arms ammunition to deadly TNT in bulk. No one ever knew exactly how much ammunition or the types of ammunition that were stored at Black Tom at any given moment.

One especially "sensitive" vessel was the barge Johnson 17, moored tight against the pier, in blatant violation of safety laws. It was heavy with 100,000 pounds of TNT and 417 cases of detonating fuses.

Security regulations were yawned at, and the actual policing of this lengthy pier was, at best, casual. Only six railroad detectives and two more from a private agency wandered the ill-lit labyrinth of warehouses, box cars and sidings. No gate sealed off the area. No pass system would trouble an intruder.

To wander about the pier, one had only to keep in the shadows. With all the warehouses, railroad cars and barges, there were plenty of shadows. The pier was a lurker's dream.

The stillness of the night was disturbed only by the troublesome drone of millions of mosquitoes. They were so bad that the guards had lighted smudge pots, again in defiance of regulations, and huddled about them. They hoped the smoke would discourage the murderous insects.

Saturday night turned into Sunday morning. The mosquitoes did not abandon their assault, merely waited, with ever-mounting appetites, on the perimeters of the smoke screen. The eight watchmen did not choose to leave the smoldering pots.

At 2:45 a.m., tongues of flame suddenly shot up from one of the loaded cars. Simultaneously, another blaze was noticed on the barge Johnson 17.

The guards, realizing that Black Tom Pier was no place for fires, started running, although one had the presence of mind to flip the switch on a lire alarm before he continued.

They pounded down the thickly creosoted planking of the long dock, across the midway bit of grubby earth and sand known as Black Tom Island, and onto the Jersey shore and Communipaw. They almost collided head-on with the first firemen to arrive at the pier head. The fire-lighting equipment included a horse-drawn pumper, a gasoline-driven "hook-and-ladder," bearing several short lengths of ladder, and a reel of hose. Two middle-aged, obviously volunteer firemen lugged a cumbersome container of some kind of chemicals.

"What's the matter?" one of the latter two wheezed, as they set down their burden.

The guards paused, drew fresh breaths, then continued running.

Meanwhile, in nearby Bayonne, a New Jersey port of warehouses, gas and oil tanks, and tenement housing, the Czechoslovakian landlady of one of many 50-cents-a-night rooming houses, Mrs. Anna Rushnak, stirred uneasily in her sleep, then awoke.

Was it something in her subconscious or was it that strange boarder of hers? His name was Michael Kristoff, distantly relative to her, a tall, slim young man of 23. His odd hours had become a matter of increasing concern to the elderly woman, ranging as they did over the entire day and night.

At this early Sunday morning hour, Mrs. Rushnak became especially curious as to his whereabouts. The hall light was burning. He hadn't come in before she retired to bed.

In these times when "spies" and "agents" might do just about anything, one couldn't be too careful. And one would do well to be suspicious of anyone, even a relative. She wondered if She shouldn't speak to her daughter, Mrs. Lulu Chapman, about him? Kristoff had also boarded with Lulu. She was still awake as the old French clock on the mantel chimed 2 o'clock. There weren't many more minutes -- just about eight, by the count, before this landlady's world started disintegrating.

At 2:08 a.m. the house shook as though an earthquake's focal point were directly below. The heavens lit up, and roared. There was a pause of seconds, then a second clap of mighty thunder.

Mrs. Rushnak pulled the sheets over her head and commenced to pray.

Millions of other residents within a radius of 50 miles of Black Tom Pier, mortally terrified, were also praying. In Manhattan, Staten Island and Brooklyn and along a 15-mile stretch of the Jersey shore, men, women and children were tossed casually out of their beds. Panes of glass were atomized in tens of thousands of homes. In all of lower Manhattan hardly a window was left in any building, including the skyscrapers.

Patrons stepping out of night clubs in New York City were brusquely hurled back against the doors by a hot, powerful blast pulsing across the bay. Scores of Philadelphia housewives, 90 miles away, raised up from their pillows to ask their husbands in shaky apprehension, "What was that?"

Conscious of "a rumbling of thunder," thousands of people in the greater New York area rushed out into the streets, clad in pajamas or nightgowns. Still others held their ears, punished by a "deafening roar," while stepping gingerly in bare feet over fragmented window glass.

In Jersey City, where the skies were a saffron hue, one witness described the holocaust as an "American Verdun. Bombs soared into the air and burst a thousand feet above the harbor into terrible yellow. Shrapnel peppered the brick walls of the warehouses, plowed the planks of the pier and rained down upon the hissing waters."

On Ellis Island, close by the scene of the blast, the Immigration Station was battered and pocked. Newly-arrived immigrants were led out of their dormitories only to be covered with hot cinders raining down from the heavens. On the same island, 90 whimpering patients were hastily removed from a government hospital for the insane.

The explosions, in diminishing key, kept up until dawn. It was not until Monday afternoon that the harbor area had calmed down and the last spirals of smoke had dissipated. Black Tom was gone completely. There wasn't a trace of the pier, the warehouses, the cars or locomotives, the barges or even of Black Tom Island itself. All were gone, reclaimed by the sullen, shallow waters of the bay.

No one could accurately assess the physical extent of the loss, or even set a price tag, though $20 million became a generally accepted guess. Loss of life, however, was singularly low: a railroad guard, a policeman and a child thrown from its crib in Jersey City. The fourth, whose body was washed ashore six weeks later, was the captain of the Johnson 17.

What had happened? An accident? One of the detectives admitted lighting the smudge pots. Two of them were immediately arrested, then released when it was realized that the pots were an unlikely trigger for the massive explosion.

Mrs. Rushnak, however, thought two and two made four. When the explosions finally subsided and dawn reddened the pall of smoke on the eastern horizon, she stepped cautiously out of bed, over the broken glass from every one of her windows, and tiptoed to Kristoff's room.

Se found him dressed, sitting on the edge of his bed, running and rerunning his fingers through his tousled shock of reddish hair, mumbling, "What I do? What I do?"

Mrs. Rushnak did not attempt to question him, but hurried to the home of Mrs. Chapman, her daughter. Together they called on old friend Captain John J. Rigney of the Bayonne Police, telling him of their suspicions. Mrs. Chapman recalled "he had s habit of going away from time to time, and everywhere he went there was an explosion." When he came home, he always seemed to have "plenty of money."

Once, the younger lady had found an opened letter in his room, written by Kristoff, addressed to some one named "Graentnor," demanding "more money."

Kristoff was arrested. H e told a semi-coherent story of working for a man named Graentnor, carrying suitcases for him. He thought these suitcases contained blueprints of factories and bridges, maybe books and money as well.

Investigators looked up Kristoff's background. He had been born in Slovakia, a subject of Austri-Hungary. H e came to America in 1899 and had worked at the Tidewater Oil Plant, near Black Tom, just before the explosion. He could offer no alibi for his whereabouts the night of the explosion. Even so, he was released as "insane but harmless."

He then enlisted in the U.S. Army.

Soon, Americans everywhere were doing the same thing. Provocations, including the explosion, in January 1917, at a munitions plant at Kingsland, N.J., finally led to United States entry into the war in Europe.

Black Tom was overridden in the public mind by greater concerns of the moment.

After the Armistice there were many corporations, primarily the Lehigh Valley Railroad, and individuals damaged by the Black Tom explosion and other disasters, who wanted redress, if possible. A Mixed Claims Commission, composed of one American, one German and an "umpire," was appointed to investigate all of the "incidents" prior to April 1917.

Black Tom's trail led, inescapably, back to Kristoff. Discharged from the Army, he was found in an Albany, New York jail, serving a sentence for theft. He admitted he had worked in the Germans' employ for "a few weeks," but offered nothing conclusive.

Released, he was followed until he turned up in jail again, for a minor offense. Ultimately, in 1928, the off-and-on pursuit of Kristoiff ended in a potter's field on Staten Island. There a corpse was exhumed, with papers identifying it as Kristoff. Teeth impressions failed, however, to match those in Army dental records. Was this or wasn't this Kristoff's body?

Other former German agents, among them Kurt Jahnke and Lothar Witzke, though now out of the country, were nonetheless located and questioned. The two, described as "one of the deadliest teams in history," had apparently done much of the work of actually secreting Rintelen's pencil bombs on outgoing ships.

Interviewed in South America (and later in China), Witzke was voluble enough since he was beyond the reach of any prosecution. Of course, he said, he "did the work in New Jersey with Jahnke when the munitions barges were blown up and the pier wrecked." He added that the two were nearly drowned bv the waves following the first blast.

Further investigation showed that two of the pier guards had been on the Germans' payroll and that Kristoff, an "intermediary,'' had asked them to relax their vigilance.

Not until 1930, however, did the case seem finally clinched when Paul Hilken, a naturalized American living in Baltimore, admitted having been "paymaster" for a number of German agents. One of them, "Graentnor," already alluded to by Kristoff, also used the name Max Hinch.

The trail that led to Hilken's confession was a damning message written in a copy of Blue Book magazine, of January 1917. The message was written in lemon juice, producing an ink that was invisible until heated.

The note was found on page 636, among the lines of the novelette, "The Yukon Trail." Citing Black Tom Terminal by name, the message told Hilken that "Kristoff, Wo1fgang and that Hoboken bunch" were to be paid, and was signed "Hinch." Hinch, or Graentnor, was a shadowy figure who was never found.

The Mixed Claims Commission decided, at last, that there must have been "foul play" behind the Black Tom explosion. Understandably, no one would ever, know whether it was actually Kristoff, Jahnke, Witzke, Graentnor, Hilken, one of the guards or possibly someone else who was the principal saboteur. Who lighted a fuse or tossed the first match or magnesium flare? The answer to this question was obviously at rest in one or more graves. The commission agreed, however, that $50 million, the greatest amount of damages in history for a case of this kind, should be apportioned among the plaintiffs.