Once the decision to act was made, the rest was easy, or so he told himself. Jonas Macphail had trained his entire life for this exact moment; he'd fired countless thousands of rounds from the primitive sidearm he carried - a Springfield Armory 1911-A1, designed by American John Moses Browning in the year 1911 (hence its designation), chambered in .45ACP, and still a popular weapon in this, the year 2009 - the era of Jonas' jurisdiction.

He knew his potential target, and the speed with which he'd have to act to avoid both detection, and defeat. He was intimately familiar with each and every detail of the moment to come, as he'd watched it play out innumerable times, in innumerable variations throughout the years of his upbringing and training.

He waited - crouched near an empty gazebo at the center of a nondescript little park in Cambridge, Massachusetts - and allowed the mingled sensations - the smell of stale beer, left by the winos who frequented the park after dark, and the sound of starlings in the black oaks above - to temporarily pull his troubled psyche away from the task that lay before him.

The three-plus pounds of blued steel resting in his windbreaker's pocket drew him back to reality, as did the blue "Gold's Gym" duffel that sat at his feet. He was oddly transfixed by the gun's simplicity; it was blocky, brutish, and thoroughly "dumb". It seemed so haphazard...so utterly sloppy to rely on the simple projection of a copper-jacketed lead slug, when so very much hung in the balance. Still, he had grown to appreciate, if not love his customized .45. Its heft provided a degree of certainty that Jonas sorely needed.

He was a Sentinel; a genetically "original", purpose-raised member of a pseudo-religious order stretching both several centuries into the past, and forward, nearly a millennium into the future, though in truth, the very concept of "time" was now more than a bit obsolete.

Jonas and his fellow Sentinels (nobody - including the Sentinels themselves - knew exactly how many individuals made up the order, or had served in its ranks throughout history) served only one purpose: the perfection of humanity via the manipulation of its actions, and subtle "correction" of incorrect or suboptimal actions across the recurring threads of countless alternate universes.

The Sentinels had traveled undetected through more than 1,300 years' worth of human history, identifying individuals, groups, and movements that might be "steered" to drive humanity in an optimal direction. The incidental casualties that resulted - whether from the occasional world war, Cultural Revolution, or genocide - were simply viewed as necessary evils...a regrettable means to a utopian end.

Each of the members of the order was selected at birth (though no one knew by whom), and raised to be singularly expert in the customs, cultures, political forces, and large-scale events (natural disasters, wars, etc.) that marked his or her specified time of influence and action. Each Sentinel's role was limited in scope, specific, and designed to pave the way for the Sentinel to follow. Their paths of action were designed to overlap one another, so as to provide a seamless blanket of influence that would, according to the decision of whatever organization had originally set the boundaries of their existence, allow the Sentinels to be present at, and hold influence over every major historical turning point in human history, since the founding of the first English colony in North America. Upon completion of their particular aspect of a mission, a Sentinel essentially "handed off" his or her era to the next in line. This overlap also provided the benefit of ready "backup" on any given mission.

What made Jonas' particular job so difficult, however, was the fact that the plan in place had failed to account for any intentional failure on the part of a Sentinel. So careful, thorough, and meticulously developed was the Sentinel protocol that there was simply no provision in place to account and adjust for a change of heart, or a decision to act in contravention of the mission; such an occurrence had never taken place, and was thought to be all but impossible. Should any of the puzzle pieces of the Sentinel mission fall out of place, the entirety of mankind's best future was under threat, and there was nothing to be done to prevent it.

Jonas knew his mission like the sound of his own breathing, and had a more than casual familiarity with that of his successor, a slightly younger man named Remy DeVillepan.

In late 2007, a physics professor at the Massachusetts Institute of Technology had begun to put to practical test a number of combined theories dealing with time travel. Einstein had, of course, proven the theoretical possibility, but it was 43 year-old Professor DeRon Thompson who would blast away the last remnants of time travel's status as science fiction.

At some point across the threads of time that linked the Sentinels, however, their leadership had determined that mankind would derive the most benefit from Dr. Thompson's work - the very thing that would bring the order into being - if he were more prompt...more focused in brining it to fruition. The real world application of his research would, if left to develop as it had originally, have taken nearly three more decades to be brought to bear on the world in any sort of practical sense. Thompson was a widower, but his 4 year-old daughter Sarah was seen as little more than a hindrance to the greater good in the eyes of whatever forces guided the hand of the Sentinel, and as such, she would need to be removed from the picture.

This, then, was Jonas' mission: under the guise of a mugging gone badly, he would kill the young girl, and wound her father. In response, Dr. Thompson would become a virtual recluse, obsessed with the notion of practical time travel, and determined to prevent his daughter's murder. Jonas would simply step out of the picture, leaving the next Sentinel to steer Dr. Thompson through his grief, and to direct his work.

Remy's job for the moment was simply to ensure that Jonas faced no unexpected intrusions...no wrinkles in the chaotic progression of time and events, which, though largely predictable, still could not account for each quirk of human behavior. He was also armed, and should circumstances prevent Jonas from completing the mission, the job would fall to him, and their roles - gunman and witness - would simply be reversed.

Jonas' attention narrowed on the nondescript maroon sedan that eased up to the curb to his right, only forty or fifty yards from his position. He could hear the sound of tires crunching on gravel, and the muffled discussions of a four year-old and her father squeezing from the slightly open passenger side window.

Their doors closing with a thump-thump, Dr. Thompson and his daughter emerged from their Toyota, and began to stroll, hand-in-hand, toward the playground that lay beyond the bandstand where Jonas knelt, readying his weapon, and running through a mental checklist that he'd prepared nearly five years earlier.

Jonas glanced to his left, where he knew he'd see Remy - sitting on a park bench, sunglass-hidden eyes surveying the background, and uncrossing his legs, preparing to step forward and "chase away" the assailant who would soon rob a man of his most treasured companion.

Jonas stepped quickly from his hiding place. Neither Thompson nor his daughter noticed him as he casually strolled to his left, toward an intersection point that would place him between the pair's destination and Remy - the helpful bystander. After taking one final glance around, Jonas turned to face his prey, slowly pulled the pistol from his left jacket pocket, and cocked the hammer.

As he brought the gun to eye-level, he gained his sight picture, and squeezed the trigger.

The first shot caught a surprised Remy in the upper chest, just below his right shoulder, and spun him around. The next two rounds hit center mass, and Remy dropped from the bench like a marionette whose strings were cut. His gun still on his fellow Sentinel, Jonas strolled quickly toward the stricken man.

Crimson flowers blossomed from three neat holes in Remy's crisp blue oxford shirt, and he stared at the sky above through widened eyes, his breathing labored, and raspy, and his lips moving in silent conversation.

At the first shot, Thompson had instinctively covered his daughter with his own body, picked her up and cradled her in his arms, and begun sprinting back to his car - his steps propelled ever faster by the crack of Jonas' follow-up shots. He never turned back to see what had happened, but called the police from his cellphone in the car.

Jonas watched as the life drained from Remy's face. Neither man said a word to the other.

As the smell of cordite and spent powder lingered in the air, Jonas carefully wiped down the pistol - though his fingerprints would have provided no help for the investigating officers speeding to the scene - and dropped it beside the dead man's park bench perch. He then pulled a blue mechanic's overall from his duffel, and stripped away the soiled sweatpants, t-shirt and jacket that had made up his uniform for the day's activities. Donning the coverall, Jonas turned, and walked to the north, disappearing in the dark alley between Ike's pizza, and the local Edward Jones branch.

The universe had just shifted, with Jonas as its pivot; his slumped shoulders and trembling hands gave away the certainty of this fact. Yet, the world around him continued apace, ignorant of the gravity of this single action - just another statistic for the FBI's yearly report to Congress.

Forty-three minutes later, as detective Marco Peluzzo lifted the ubiquitous crime scene tape and examined the scene, he was approached by one of the uniformed officers on scene. The officer carried a large brown paper sack with the word "evidence" scrawled in sloppy Sharpie on one side.

"Hey Detective..." said the officer, "Dude used a nice gun for the hit, whoever he was. Delta hammer, full-length guide rod, night sights - the whole nine yards, y'know?"

"Yeah, that's what Lt. Vinson said. Not exactly your typical Saturday night special, huh?" Replied the graying detective with a grin.

At this, the officer's head cocked to one side, and his eyes narrowed. "You seen the engraving on the piece?"

"Nope. What's up? We got some kind of a vain button man on our hands here?" asked the detective.

"Dunno, Lieutenant. You ever see the word ' Jobbernowl' before, sir?"