“Like the cold, pinkskin?” shouted an Andorian from somewhere in the crowded marketplace. Daniels simply turned and kept his gloved hands on his collar, partly obscuring his face, as he ducked past an open cooking station—some kind of deep freshwater shellfish, probably pulled out from beneath a glacial lake—and gently brushed past an old Andorian woman. Several small tables choked the space on the other side, where many Andorians ate and argued. Eyes followed the team, but most of the people in this squalid marketplace were too busy dealing with their own personal business to pry too much into the strangers in their midst.

Daniels moved to hug the cold wall of the massive cave complex. He surreptitiously checked his palm-sized tricorder, then nodded to his recruits.

“In about twenty minutes, there’ll be an impromptu speech by Banis Ch’thiriv, a labor organizer in this area. He generates some support for the nascent Coalition of Planets that lays the groundwork for the later Federation. While his reception here is lukewarm, he’s assassinated about five minutes later by a member of the Terra Prime faction. The assassin is killed by security forces but it takes Banis five days to die from his injuries. During that time he records a set of moving dialogs asking people to become better, to root out these conflicts and do so by finding common ground with Humans—and others—who share a desire for a peaceful future, rather than letting this event turn into a flashpoint for extremists,” Daniels explained.

Keero piped up hesitantly, asking, “Are we here to save him?”

“No,” said Daniels flatly. “Banis’ death galvanizes otherwise uncommitted parties to stand against the Terra Prime faction and other xenophobic ultranationalist groups. The Andorian people drive those groups into obscurity and some members even defect in disgust; the same happens on Earth, even as the Vulcans go through their Reformation. The seeds of old, fascistic impulses are pulled out by the root and destroyed, and new governments form with goals of mutual cooperation.”

“Then we will be forced to observe his slow death?” said Keero with an anguished expression.

Daniels remained neutral and unreadable. “Yes. I’m not saying because it’s right, but because of the alternative. But let’s talk about this in broader terms.” He knocked his boots against the wall to force some of the slush out of the treads. “On Earth in the 20^th century, these boot soles would be made of rubber. And that raises a great question for temporal agents: Why don’t we go back in time and assassinate Leopold II?”

Lieutenant Sokhanya, a dark-haired Cambodian human woman from the 24^th century, replied, “Don’t you mean Hitler? That’s the famous formulation—time travelers assassinating Hitler.”

“Nope,” said Daniels, setting his feet back down and leaning against the wall casually. “Leopold II. King of Belgium. Oversaw Belgian interests in the Congo, part of the African continent of Earth. As part of his mission to extract precious resources in the Congo, Leopold authorized widespread exploitation and abuse of the local population. Estimates place the death toll at ten million people. Hitler became famously ensconced in history books because of a foible of late twentieth-century Earth culture: the mass murders in the Congo didn’t happen in Europe or North America, so people of the era didn’t bother learning about them. This skewed the writing of history and journalism from the era, and as a result Leopold II, despite overseeing a regime of monumental cruelty and violence, gets nary a mention in Earth history of the time. Not that this absolves the Reich, of course; but history has no shortage of bad actors.”

Keero glanced at his own tricorder to check for temporal incursions, but there were no signals—just the steady pulse of the quantum waveform from the underlying atomic motion of the universe. Daniels leaned over and pointed at Keero’s tricorder. “All quiet, right? Sooo…” He gestured in a circling motion for Keero to finish his sentence, a teacher guiding a student.

Keero slowly replied, “Either the incursion hasn’t happened yet, or it has already happened far enough back that we are not seeing any residual energy.”

Daniels nodded. “Right. And if a temporal incursion were going to happen within the next few minutes, we’d already see tachyons flooding backward. Which means…” He turned to look at Lieutenant Sokhanya.

The lieutenant glanced up from her tricorder and said, “It must’ve already happened, but possibly days or weeks ago.”

Daniels nodded again. “Also right. So where’s our temporal intruder? Look around. Who do you see?”

The third student, an Orion woman, finally piped up. “Just Andorians as far as the eye can see. This is a marketplace in a poor, crowded part of town. It actually reminds me of the Orion quarter on Qo’noS.”

Daniels gave a brief half-smile. “You’ll have to do better than that, Drij. Where’s our temporal intruder? Who’s been here for days?”

Drij scanned the marketplace again, once with her tricorder, once with her eyes. “I don’t know, this place is just packed with people… people. The intruder’s been here for days, on 22^nd-century Andoria—he looks like an Andorian!”

“Right the third time,” said Daniels, his grin tightening as he took on an impassive expression. “And all we know is that the intruder is going to interfere with this point in time. We have to stop that interference, no matter what form it takes.” He put his tiny tricorder back in his pocket and ran his fingers over his sleeve, ostensibly brushing off snow, but in truth checking the small holdout phaser concealed in the lining.

“If we are able to save Baris, will that not still protect the timeline?” asked Keero.

Daniels pointed to a ledge on the opposite wall and to a tent holding swaths of colorful fabric and clothing. “No. Events have to unfold as they originally did. Every alteration to history creates new quantum splits—new timelines and new universes. But the energy for those to exist still has to be accounted for. Too many splits and the cosmos itself risks collapse. Our job isn’t to ‘fix’ history. It’s to stop other people from breaking the past and potentially ending the universe.”

With a nod, Daniels issued orders. “Drij, you and Keero head to the clothier’s shop. That’s the spot where the historical shooter is concealed. Make sure he doesn’t get intercepted or killed. Sokhanya, you’re with me. We’re going to check that ledge, which is where I’m guessing our uninvited guest will make an appearance.”

The group split up, Drij and Keero moving into the walls of textiles as Daniels ducked his head and, with Sokhanya directly behind him, pushed through the crowd to the far side of the cavern and made his way up a rickety metal walkway to the ledge above.

Keero wasn’t sure what to look for, so he simply started examining the textiles. He picked up a swatch of long golden fabric, turning it over in his hands, while trying to keep an eye out for anyone looking angry or guarded… or armed. The shopkeeper, an Andorian woman with milky eyes and an elaborately-decorated tunic, approached him with the hope of a sale. “You like it?” she said eagerly, her antenna leaning forward. “We can make a trade, offworlder.”

Drij smoothly interjected herself, giving Keero a knowing nod as he limply let go of the fabric. “I’m quite interested,” she said. “Do you have anything in a nice silver or dark blue that would complement my skin tone?” she asked, smoothly covering so that Keero could continue his search.

Keero stepped aside as the shopkeeper turned her attention to Drij. The sociable Orion easily took up the shopkeeper’s attention, freeing up Keero to continue looking for the would-be assassin. Realizing that the assassin would be less likely to take up a spot inside of the shop if it was already crowded, he drifted next door into a different kiosk selling a variety of knick-knacks, icons, trinkets, and jewelry. He glanced back at Drij, then looked up toward the ledge on the far side of the cavern.

In the distance, Daniels appeared to be engaged in a struggle with an Andorian. On the icy ledge, the two fought for control of an ushaan-tor - the ice-cutting tool famous for use in Andorian duels of honor. Sokhanya struck the Andorian from the side, knocking the weapon from his hand, and Daniels took him to the ground. The two rolled back into the cleft and Sokhanya scooped up the fallen weapon, then also ducked back into the shadows. Only a few seconds later, Sokhanya staggered out, hands covered in blue blood, before Daniels pulled her back into obscurity. Below, the Andorian crowd paid little attention; the ledge was high enough up the wall to be out of the line of sight of most of the people, and besides, who cared if a visitor was stabbed by one of the locals?

“Daniels to team,” came his call very quietly over the comm. “We’ve neutralized the temporal intruder. Get out of the situation, let history play out. We’ll meet up back at the fishmonger’s shop that we passed on the way in.”

Drij quickly told the cloth-seller that she’d return with some trade goods of her own and extricated herself. Keero watched her go, then counted out another eight seconds so that his departure didn’t match her timing. He turned and immediately bumped into a smooth, expressionless, bland-looking Andorian man. “Sorry,” he mumbled as he sidestepped out into the street. The Andorian’s expression changed to burning, hate-filled eyes, his lips curving down into a frown, his antennae shrinking back into a defensive posture, and he stepped into the clothier’s shop, still watching Keero the whole time. Keero didn’t see a weapon, but his body language was clear: He was ready to fight.

Ducking his head, Keero shuffled quickly down the thoroughfare, sliding through the crowds and trying to catch up with Drij.

“Good,” came Daniels’ calm voice over the comm. “Meet up here and prepare for extraction. Don’t get distracted.”

Despite Daniels’ admonition, Keero couldn’t help but look over his shoulder. Atop a metal stage, an old Andorian man had started shouting at the crowd—Banis, by all appearances. The angry man leaned against a beam supporting the clothier’s shop, listening and clearly upset by the unfolding speech. A few members of the crowd had turned to watch the spontaneous harangue. Keero could feel a sense of dread, of oncoming distress, as he knew how this would unfold.

A hand grabbed his arm, hard, and yanked. He attempted to break free, twisting against the grab as he’d learned in hand-to-hand defense training, before he noticed that it was Daniels, face close, pulling him along.

“We have to go, Keero,” said the temporal agent. “Let it play out. We can’t change it without risking big changes, and if that happens, we put the entire universe at risk.”

“But…” Keero’s mental computer whirred, spitting out hundreds of calculations and possibilities that were singularly unhelpful. His thoughts were only half-formed as he spoke, “… that is… just physics. I do not want the universe to end. But this is not about universal laws. It is about hatred, and bigotry, and murdering people just because they are not like you.”

“And stopping that is a war worth fighting,” answered Daniels as he released his grip on Keero’s arm. He walked briskly toward the fishmonger stall where Drij and Sokhanya waited, and gestured for Keero to come with him. “We fight it with our ideals, and we fight it with fists when we have to. But blowing up the universe to spite these people is a losing proposition. We have to make sure that we have a world to live in, and that means keeping the seams together while we stop the people who want to make it worse.”

Keero finally nodded. “We have all of these predictive models; can we not figure out what changes are safe to make? Where we could stop terror, change history to make it better?”

“We’re not the only ones with that technology,” said Daniels tersely. “That’s why there are these incursions. Other species develop their own time-travel technology independently, and they all have their own agendas.” As Keero’s frown deepened, Daniels elaborated.  “Groups like the Temporal Liberation Front believe that they can irresponsibly alter the timeline without consequences. The Terrans from the Mirror Universe have their own time agents, working to change our history as well as their own, all to spread their agenda of cruelty. Posthuman and metaphysical entities like the Q and the Guardian of Forever can change time, apparently without the limitations that we have, and they’re well beyond our means to control - or even monitor. Faced with such opposition, you can see why our mission is so important.  It’s on us to maintain the timeline, keep everyone alive, and make sure the universe doesn’t fall apart from too much meddling.”

“That’s why you can’t go back and change things. You can’t stop the past. You can’t go home again and you can’t return to your own time, because you’d change things and the universe would tear. You’d feel the need to make things different and instead you’d become one of the temporal incursions that risks unraveling the underlying quantum energy of reality,” said Daniels as the two reunited with Sokhanya and Drij.

Sokhanya was busy wiping blue blood from her hands with a cloth while Drij languidly draped herself on a nearby table to draw attention away from the mess. “I caught the last part of that,” said Sokhanya as she dumped the cloth into a recycler. “What about all the time changes that we just… let go by? The Enterprise’s trips to the past? The Iconian War?”

Daniels sighed heavily and said, “You’ll learn more about that in Advanced Paradox Theory. Certain pre-temporal agency events are considered part of the ordered sequence now and we can’t revisit them; it’s like reopening an old wound. We’re minimizing collateral damage.”

Back at the other end of the marketplace a disruptor whined and the speaker staggered back. Another shot and he fell. People scattered, shouting and pushing.

Daniels watched impassively as history unfolded. “We don’t have to like it. But until we have a better alternative, we have to live with it. We’re watching history… but we have to hope that while we’re fighting this fight, there are people who are willing to make that history happen, good people willing to fight for a better tomorrow, one that gives us the chance to step up and make sure that we still have a world to live in.” As the crowd swirled and attention was diverted, he keyed his transponder and the temporal agents were lifted out of the chaos to the safely removed distance of their own time.