AT APPROXIMATELY the same time that Elliott Freemantle was savoring success, an embittered, thwarted, former building contractor named D. O. Guerrero was surrendering to failure.

Guerrero was fifteen miles or so from the airport, in a locked room of a shabby walk-up apartment on the city's South Side. The apartment was over a noisome, greasy-spoon lunch counter on 51st Street, not far from the stockyards.

D. 0. Guerrero was a gaunt, spindly man, slightly stoop-shouldered, with a sallow face and protruding, narrow jaw. He had deep-set eyes, pale thin lips, and a slight sandy mustache. His neck was scrawny, with a prominent Adam's apple. His hairline was receding. He had nervous hands, and his fingers were seldom still. He smoked constantly, usually lighting a fresh cigarette from the stub of the last. At the moment he needed a shave and a clean shirt, and was perspiring, even though the room in which he had locked himself was cold. His age was fifty; he looked several years older.

Guerrero was married, and had been for eighteen years. By some standards, the marriage was good, if unspectacular. D.O. (through most of his life he bad been known by his initials) and Inez Guerrero accepted each other equably, and the idea of coveting some other partner seemed not to occur to them. D. O. Guerrero, in any case, had never been greatly interested in women; business, and financial maneuvering, occupied his thoughts far more. But in the past year, a mental gulf had opened between the Guerreros which Inez, though she tried, was unable to bridge. It was one result of a series of business disasters which reduced them from comparative affluence to near poverty, and eventually forced a succession of moves---first from their comfortable and spacious, if heavily mortgaged, suburban home to other quarters less pretentious, and later still to this seamy, drafty, cockroach-infested, two-room apartment.

Even though Inez Guerrero did not enjoy their situation, she might have made the best of it if her husband had not become increasingly moody, savagely bad tempered, and at times impossible to talk with. A few weeks ago, in a rage, he had struck Inez, bruising her face badly, and though she would have forgiven him, he would neither apologize nor discuss the incident later. She feared more violence and, soon after, sent their two teen-age children---a boy and a girl---to stay with her married sister in Cleveland. Inez herself stayed on, taking a job as a coffee-house waitress, and although the work was hard and the pay small, it at least provided money for food. Her husband seemed scarcely to notice the children's absence, or her own; his mood recently had been a deep and self-contained dejection.

Inez was now at her job. D. O. Guerrero was in the apartment alone. He need not have locked the door of the small bedroom where he was occupied, but had done so as an added guarantee of privacy, even though he would not be there for long.

Like others this night, D. O. Guerrero would shortly leave for the airport. He held a confirmed reservation, plus a validated ticket---for tonight---on Trans America Flight Two to Rome. At this moment, the ticket was in a pocket of his topcoat, also in the locked room, slung over a rickety wooden chair.

Inez Guerrero had no knowledge of the ticket to Rome, nor did she have the slightest inkling of her husband's motive in obtaining it.

The Trans America ticket was for a round trip excursion which normally cost four hundred and seventy-four dollars. However, by lying, D. O. Guerrero had obtained credit. He had paid forty-seven dollars down, acquired by pawning his wife's last possession of any value---her mother's ring (Inez had not yet missed it)---and promised to remit the balance, plus interest, in monthly installments over the next two years.

It was highly unlikely that the promise would ever be fulfilled.

No self-respecting finance company or bank would have loaned D. O. Guerrero the price of a bus ticket to Peoria, leave alone an airline fare to Rome. They would have investigated his background thoroughly, and discovered that he had a long history of insolvency, a parcel of long-standing personal debts, and that his homebuilding company, Guerrero Contracting Inc., had been placed in bankruptcy a year earlier.

An even closer check into Guerrero's tangled finances might have disclosed that during the past eight months---using his wife's name---he had attempted to raise capital for a speculative land deal, but failed to do so. In course of this failure he had incurred even more debts. Now, because of certain fraudulent statements, as well as being an undischarged bankrupt, exposure, which seemed imminent, would involve criminal prosecution and almost certainly a prison term. Slightly less serious, but just as immediate, was the fact that the rent of this apartment, wretched as it was, was three weeks overdue, and the landlord had threatened eviction tomorrow. If evicted, they would have nowhere else to go.

D. O. Guerrero was desperate. His financial rating was minus zero.

Airlines, though, were notably easygoing about extending credit; also, if a debt went sour they were usually less tough in collection procedures than other agencies. This was calculated policy. It was based on the fact that fare-paying air travelers, over the years, had proven themselves an unusually honest cross-section of society, and bad debt losses of most airlines were remarkably low. Deadbeats like D. O. Guerrero troubled them rarely; therefore they were not geared---because it was not worth while---to defeat the kind of subterfuge he had used.

He avoided, by two simple means, more than a cursory credit investigation. First, he produced an "employer's reference" which he had typed himself on the letterhead of a defunct company he once operated (not the bankrupt one), the company's address being his own post office box. Second, in typing the letter he deliberately misspelled his surname, changing the initial from "G" to "B," so that a routine consumer credit check of "Buerrero" would produce no information, instead of the harmful data recorded under his correct name. For further identification he used his Social Security card and driver's license, on both of which he carefully changed the same initial beforehand, and had since changed it back again. Another point he remembered was to make sure that his signature on the time payment contract was indecipherable, so it was not clear whether he had signed "G" or "B."

The misspelling was perpetuated by the clerk who yesterday made out his airline ticket in the name of "D. O. Buerrero," and D. O. Guerrero had weighed this carefully in light of his immediate plans. He decided not to worry. If any query was raised afterward, the error of a single letter, both on the "employer's reference" and the ticket, would appear to be a genuine mistake. There was nothing to prove he had arranged it deliberately. In any case, when checking in at the airport later tonight, he intended to have the spelling corrected---on the Trans America flight manifest as well as on his ticket. It was important, once he was aboard, to be sure there was no confusion about his correct identity. That was part of his plan, too.

Another part of D. O. Guerrero's plan was to destroy Flight Two by blowing it up. He would destroy himself along with it, a factor which did not deter him since his life, he reasoned, was no longer of value to himself or others.

But his death could be of value, and he intended to make sure it was.

Before departure of the Trans America flight, he would take out flight insurance for seventy-five thousand dollars, naming his wife and children as beneficiaries. He rationalized that he had done little for them until now, but his final act would be a single transcendent gesture on their behalf. He believed that what he was doing was a deed of love and sacrifice.

In his warped, perverted mind---driven by desperation---he had given no thought to other passengers who would be aboard Flight Two, nor to the aircraft's crew, all of whose deaths would accompany his own. With a psychopath's total lack of conscience he had considered others only to the extent that they might circumvent his scheme.

He believed he had anticipated all contingencies.

The business about his ticket would not matter once the aircraft was en route. No one could prove he had not intended to pay the installments he contracted for; and even if the fake "employer's reference" was exposed---as it probably would be---it demonstrated nothing except that he had obtained credit under false pretenses. That, in itself, would have no bearing on a subsequent insurance claim.

Another thing was that he deliberately bought a round-trip ticket to create the appearance of not only intending to complete the outward flight, but also to return. As to choosing a Rome flight, he had a second cousin in Italy whom he had never seen, but occasionally talked of visiting---a fact which Inez knew. So at least there would seem an element of logic to his choice.

D. O. Guerrero had had his plan in mind for several months while his fortunes were worsening. During that time he studied carefully the histories of air disasters where airliners were destroyed by individuals seeking to profit from flight insurance. The number of instances was surprisingly large. In all cases on record the motive had been exposed by post-crash investigation and, where conspirators remained alive, they were charged with murder. The flight insurance policies of those involved had been invalidated.

There was no means of knowing, of course, how many other disasters, where causes remained unknown, had been the result of sabotage. The key factor was the presence or absence of wreckage. Wherever wreckage was recovered, trained investigators pieced it together in an attempt to learn its secrets. They usually succeeded. If there was an explosion in mid-air, its traces remained, and the nature of the explosion could be determined. Therefore, D. O. Guerrero reasoned, his own plan must preclude the recovery of wreckage.

This was the reason he had selected Trans America's non-stop flight to Rome.

A large portion of the journey of Flight Two---The Golden Argosy---was above ocean, where wreckage from a disintegrated airplane would never be found.

Using one of the airline's own passenger brochures which conveniently showed air routes, aircraft speeds, and even had a feature called Chart Your Own Position, Guerrero calculated that after four hours' flying---allowing for average winds---Flight Two would be over mid-Atlantic. He intended to check the calculation and amend it, if necessary, as the journey progressed. He would do so, first by noting the exact time of takeoff, then by listening carefully to the announcements which captains always made over cabin p.a. systems about the aircraft's progress. With the information it would be a simple matter to decide if the flight was behind schedule, or ahead, and by how much. Finally, at approximately a point he had already decided on---eight hundred miles east of Newfoundland---he would trigger an explosion. It would send the aircraft, or what remained of it, plummeting toward the sea.

No wreckage could ever be found.

The debris of Flight Two would remain forever, hidden and secret, on the Atlantic Ocean floor. There would be no examination, no later exposure of the cause of the aircraft's loss. Those left might wonder, question, speculate; they might even guess the truth, but they could never know.

Flight insurance claims---in the absence of any evidence of sabotage---would be settled in full.

The single element on which everything else hinged was the explosion. Obviously it must be adequate to destroy the airplane, but---equally important---it must occur at the right time, For the second reason D. O. Guerrero had decided to carry the explosive device aboard and set it off himself. Now, within the locked bedroom, he was putting the device together, and despite his familiarity---as a building contractor---with explosives, was still sweating, as he had been since he started a qLiarter of an hour ago.

There were five main components---three cartridges of dynamite, a tiny blasting cap with wires attached, and a single cell transistor radio battery. The dynamite cartridges were Du Pont Red Cross Extra---small but exceedingly powerful, containing forty percent nitroglycerin; each was an inch and a quarter in diameter and eight inches long. They were taped together with black electrician's tape and, to conceal their purpose, were in a Ry-Krisp box, left open at one end.

Guerrero had also laid out several other items, carefully, on the ragged coverlet of the bed where he was working. These were a wooden clothespin, two thumbtacks, a square inch of clear plastic, and a short length of string. Total value of the equipment which would destroy a six and a half million dollar airplane was less than five dollars. All of it, including the dynamite---a "leftover" from D. O. Guerrero's days as a contractor---had been bought in hardware stores.

Also on the bed was a small, flat attache case of the type in which businessmen carried their papers and books when traveling by air. It was in this that Guerrero was now installing the explosive apparatus. Later, he would carry the case with him on the flight.

It was all incredibly simple. It was so simple, in fact, Guerrero thought to himself, that most people, lacking a knowledge of explosives, would never believe that it would work. And yet it would---with shattering, devastating deadliness.

He taped the Ry-Krisp box containing the dynamite securely in place inside the attache case. Close to it he fastened the wooden clothespin and the battery. The battery would fire the charge. The clothespin was the switch which, at the proper time, would release the current from the battery.

His hands were trembling. He could feel sweat, in rivulets, inside his shirt. With the blasting cap in place, one mistake, one slip, would blow himself, this room, and most of the building, apart, here and now.

He held his breath as he connected a second wire from the blasting cap and dynamite to one side of the clothespin.

He waited, aware of his heart pounding, using a handkerchief to wipe moisture from his hands. His nerves, his senses, were on edge. Beneath him, as he sat on the bed, he could feel the thin, lumpy mattress. The decrepit iron bedstead screeched a protest as he moved.

He resumed working. With exquisite caution, he connected another wire. Now, only the square inch of clear plastic was preventing the passage of an electric current and thereby an explosion.

The plastic, less than a sixteenth of an inch thick, had a small hole near its outer edge. D. O. Guerrero took the last item left on the bed---the string---and passed one end through the hole in the plastic, then tied it securely, being cautious not to move the plastic. The other end of the string he pushed through an inconspicuous hole, already drilled, which went through to the outside of the attache case, emerging under the carrying handle. Leaving the string fairly loose inside the case, on the outside he tied a second knot, large enough to prevent the string from slipping back. Finally---also on the outside---he made a finger-size loop, like a miniature hangman's noose, and cut off the surplus string.

And that was it.

A finger through the loop, a tug on the string! Inside the case, the piece of plastic would fly out from the head of the clothespin, and the thumstacks would connect. The electric current would flow, and the explosion would be instant, devastating, final, for whomever or whatever was nearby.

Now that it was done, Guerrero relaxed and lit a cigarette. He smiled sardonically as he reflected again on how much more complicated the public---including writers of detective fiction---imagined the manufacture of a bomb to be. In stories he had read there were always elaborate mechanisms, clocks, fuses, which ticked or hissed or spluttered, and which could be circumvented if immersed in water. In reality, no complications were required---only the simple, homely components he had just put together. Nor could anything stop the detonation of his kind of bomb---neither water, bullets, nor bravery---once the string was pulled.

Holding the cigarette between his lips, and squinting through its smoke, D. O. Guerrero put some papers carefully into the attache case, covering the dynamite, clothespin, wires, battery, and string. He made sure the papers would not move around, but that the string could move freely under them. Even if he opened the case for any reason, its contents would appear innocent. He closed the case and locked it.

He checked the cheap alarm clock beside the bed. It was a few minutes after 8 P.M., a little less than two hours to flight departure time. Time to go. He would take the subway uptown to the airline terminal, then board an airport bus. He had just enough money left for that, and to buy the flight insurance policy. The thought reminded him that he must allow sufficient time at the airport to get insurance. He pulled on his topcoat quickly, checking that the ticket to Rome was still in the inside pocket.

He unlocked the bedroom door and went into the mean, shabby living room, taking the attache case with him, holding it gingerly.

One final thing to do! A note for Inez. He found a scrap of paper and a pencil and, after thinking for several seconds, wrote:

I won't be home for a few days. I'm going away. I expect to have some good news soon which will surprise you.

He signed it D.O.

For a moment he hesitated, softening. It wasn't much of a note to mark the end of eighteen years of marriage. Then he decided it would have to do; it would be a mistake to say too much. Afterward, even without wreckage from Flight Two, investigators would put the passenger list under a microscope. The note, as well as all other papers he had left, would be examined minutely.

He put the note on a table where Inez would be sure to see it.

As he went downstairs D. O. Guerrero could hear voices, and a jukebox playing, from the greasy-spoon lunch counter. He turned up the collar of his topcoat, with the other hand holding the attache case tightly. Under the carrying handle of the case, the loop of string like a hangman's noose was close to his curled fingers.

Outside, as he left the South Side building and headed for the subway, it was still snowing.