“Hm,” said Varagan. “We’ll go into that in more detail. First describe your assignment. Just what were you doing last century in Cajamarca?”

  The later name of the town, observed a distant part of Tamberly, while his automaton consciousness replied: “I told you, I’m a field historian, gathering data on the period of the Conquest.” It was for more than the sake of science. How could the Patrol police the time lanes and maintain the reality of events unless it knew what those events were? Books were often misleading, and many a key happening was never chronicled. “The corps got me accredited—as Estebán Tanaquil, a Franciscan friar—accredited to Pizarro’s expedition when he returned in 1530 from Spain to America.” Before Waldseemüller bestowed that name. “I was simply to observe, recording as much as I was able unbeknownst.” And do what heartbreakingly slight things he could to lighten, the tiniest bit, the brutality. “You must know, too, those years will loom large in history—futureward of my home century, pastward of yours—when the Resurgents call on their Andean heritage.”

  Varagan nodded. “Indeed,” he said conversationally. “If matters had gone otherwise, why, already the twentieth century might be very different.” He grinned. “Suppose, for example, the succession after Inca Huayna Capac had not been in dispute, Atahualpa in a state of civil war with his rivals, when Pizarro arrived. That minuscule gang of Spanish adventurers could not possibly have overthrown the empire by themselves. The Conquest would have required more time, more resources. This would have affected the balance of power in Europe, where the Turks were pressing inward while the Reformation broke what scant unity Christendom had possessed.”

  “Is that your aim?” In a vague way Tamberly knew he should be furious, aghast, anything but apathetic. He barely had the curiosity to ask the question.

  “Perhaps,” Varagan taunted. “However, the men who found you were only scouts in advance of a much more modest enterprise, bringing Atahualpa’s ransom here. That would be quite upsetting in itself, of course.” He laughed. “But it might preserve those priceless works of art. You were content to make holograms of them for people uptime.”

  “For all humankind,” said Tamberly automatically.

  “Well, for such of it as can be allowed to enjoy the fruits of time travel, under the watchful eye of the Patrol.”

  “Bring the treasure…here?” fumbled Tamberly. “Now?”

  “Temporarily. We’ve camped where we are because it’s a convenient base.” Varagan scowled. “The Patrol is too vigilant in our original milieu. Arrogant swine!” Calm again: “As isolated as Machu Picchu is at present, it will not be noticeably affected by changes in the near past—for instance, by such a detail as Atahualpa’s ransom unaccountably disappearing one night. But your associates will be in full quest of you, Tamberly. They’ll follow up every last clue they can find. Best we have that information at once, to forestall any moves of theirs.”

  I should be shaken to the roots of my soul. This utter, absolute recklessness—risking loops in the world lines, temporal vortices, destruction of the whole future—No, not risking. Deliberately bringing it about. But I cannot feel the horror. The thing that squats on my skull holds down my humanity.

  Varagan leaned forward. “Therefore let us discuss your personal history,” he said. “What do you consider your home? What family have you, friends, ties of any kind?”

  The questions quickly became knife-sharp. Tamberly watched and listened while their skilled wielder cut from him detail after detail. When something especially interested Varagan, he pursued it to the end. Tamberly’s second wife ought to be safe; she was also in the Patrol. His first wife was remarried, out of his life. But oh, God, his brother, and Bill’s own wife, and he heard himself confess that his niece was like a daughter to him— The doorway darkened. Luis Castelar bounded through.

  His sword slashed. The guard there buckled, crumpled, fell and lay squirming. Blood spouted from his throat, its red like the shriek he could no longer sound forth.

  Raor dropped the control box and snatched for her sidearm. Castelar reached her. His left fist smashed at her jaw. She staggered back, sagged, went to the floor and gaped up at him, stunned. His blade sang even as she dropped. Varagan was on his feet. Incredibly quick, he dodged a cut that would have laid him open. The room was too cramped for him to get past. Castelar stabbed. Varagan clutched his belly. Blood squirted between his fingers. He leaned against the wall and shouted.

  Castelar wasted no time finishing him. The Spaniard ripped the helmet off Tamberly. It thudded to the floor. Wholeness of spirit broke like a sunbeam into the American.

  “Get us away!” Castelar rasped. “The witch-horse outside—”

  Tamberly reeled from his chair. His knees would barely hold him. Castelar’s free arm gave support. They stumbled into the open. The timecycle waited. Tarnberly crawled onto the front saddle, Castelar leaped to the rear. A man in black appeared in the courtyard gateway. He yelled and reached for his weapon.

  Tamberly slapped the console.

  11 May 2937 B.C.

  Machu Picchu was gone. Wind surrounded him. Hundreds of feet below lay a river valley, lush with grass and groves. Ocean gleamed in the distance.

  The cycle dropped. Air brawled. Tamberly’s hands sought the gravity drive. The engine awoke. The fall stopped. He brought the vehicle to a smooth and silent landing.

  He began to shake. Darkness went in rags before his eyes.

  The reaction passed. He grew aware of Castelar standing on the ground beside him, and the Spaniard’s sword point an inch from his throat.

  “Get off that thing,” Castelar said. “Move carefully, your arms up. You are no holy man. I think you may be a magician who should burn at the stake. We will find out.”

  3 November 1885

  A hansom cab brought Manse Everard from Dalhousie & Roberts, Importers—which was also the Time Patrol’s London base in this milieu—to the house on York Place. He mounted the stairs through a dense yellowish fog and turned the handle on a doorbell. A maidservant let him into a wainscoted anteroom. He gave her a card. She was back in a minute to say that Mrs. Tamberly would be pleased to receive him. He left his hat and overcoat on a rack and followed her. Interior heating failed to keep out all the dank chill, which made him for once glad to be dressed like a Victorian gentleman. Usually he found such clothes abominably uncomfortable. Otherwise this was, on the whole, a marvelous era to live in, if you had money, enjoyed robust health, and could pass for an Anglo-Saxon Protestant.

  The parlor was a pleasant, gaslit room, lined with books and not overly cluttered with bric-a-brac. A coal fire burned low. Helen Tamberly stood close, as if in need of what cheer it offered. She was a small reddish-blond woman; the full dress subtly emphasized a figure that many doubtless envied. Her voice made the Queen’s English musical. It wavered a little, though. “How do you do, Mr. Everard. Please be seated. Would you care for tea?”

  “No, thanks, ma’m, unless you want some.” He made no effort to dissemble his American accent. “Another man is due here shortly. Maybe after we’ve talked with him?”

  “Certainly.” She nodded dismissal to the maid, who left the door open behind her. Helen Tamberly went to close it. “I hope this doesn’t shock Jenkins too badly,” she said with a wan smile.

  “I daresay she’s grown used to somewhat unconventional ways around here,” Everard responded in an effort to match her self-possession.

  “Well, we try not to be too outré. People tolerate a certain amount of eccentricity. If our front were upper class, rather than well-to-do bourgeois, we could get away with anything; but then we’d be too much in the public eye.” She stepped across the carpet to stand before him, fists clenched at her sides. “Enough of that,” she said desperately. “You’re from the Patrol. An Unattached agent, am I right? It’s about Stephen. Must be. Tell me.”

  Without fear of eavesdroppers, he continued in the English language, which might sound gentler in her ears than Temporal. “Yes. Now we don’t yet know anything for sure. He’s—missing. Failed to report in. I suppose you remember that was to have been in Lima late in 1535, several months after Pizarro founded it. We have an outpost there. Discreet inquiries turned up the fact that the friar Estebán Tanaquil vanished mysteriously two years before, in Cajamarca. Vanished, mind you, not died in some accident or affray or whatever.” Bleakly: “Nothing as simple as that.”

  “But he could be alive?” she cried.

  “We may hope. I can’t promise more than that the Patrol will try its damnedest—uh, pardon me.”

  She gave a broken laugh. “That’s all right. If you’re from Stephen’s milieu, everybody’s careless with speech, true?”

  “Well, he and I were both born and raised in the USA, middle twentieth century. That’s why I’ve been asked to lead this investigation. A background shared with your husband just might give me some useful insight.”

  “You were asked,” she murmured. “Nobody gives orders to an Unattached agent, nobody less than a Danellian.”

  “That’s not quite correct,” he said awkwardly. Sometimes his status—assigned to no particular milieu, but free to go anywhere and anywhen there was need and act on his own judgment—embarrassed him. He was by nature unpretentious, a meat-and-potatoes kind of man.

  “Good of you to agree,” she said, and blinked hard against tears. “Do please be seated. Smoke if you wish. Are you quite sure you wouldn’t care for tea and biscuits or perhaps a spot of brandy?”

  “Maybe later, thanks. But I will avail myself of my pipe.” He waited till she sat down by the hearth to take the armchair opposite, which must be Steve Tamberly’s. The fire quivered blue between them.

  “I’ve been in on a few cases like this in the past—my lifeline past, that is,” he began cautiously. “It’s desirable to start by learning as much as possible about the person concerned. That means talking with those close to him or her. So I’ve come a tad early today, hoping we could get acquainted. An agent who’s been on the spot will be along in a while to tell us what he discovered. I assumed you wouldn’t mind.”

  “Oh, no.” She drew breath. “But tell me, please. I’ve always had difficulty understanding, even when I think in Temporal. My father was a physics don, and it’s hard to set aside the strict logic of cause and effect he drilled into me. Stephen…encountered trouble somehow, in sixteenth-century Peru. Maybe the Patrol can save him, maybe it can’t. Whatever, though, whatever the result is…the Patrol will know. There’ll be a report in the files. Can’t you go at once and read it? Or, or skip ahead in time and ask your future self? Why must we go through this?”

  Upbringing or no, she must be hideously shaken to raise such a question, she who had also been trained at that academy back in the Oligocene period—back before there was any human history for its existence to upset. Everard didn’t think the less of her. Rather, it made him appreciate the courage that maintained calmness. And, after all, her work did not expose her to the paradoxes and hazards of mutable time. Nor had Tamberly experienced them—he had been a straightforward, if disguised, observer—till suddenly they laid hold on him.

  “You know that’s forbidden.” He kept his tone soft. “Causal loops can too easily turn into temporal vortices. Annulment of the whole effort would be the least of the disasters we’d risk. And it’d be futile, anyway. Those records, those memories could be of something that never happened. Just think how our actions would be influenced by what we believed was foreknowledge. No, we’ve got to go through with our jobs in as nearly causational a way as we possibly can, in order to make our successes or failures real.”

  For reality is conditional. It is like a wave pattern on a sea. Let the waves—the probability-waves of ultimate underlying quantum chaos—change their rhythm, and abruptly that tracery of ripples and foam-swirls will be gone, transformed into another. Already in the twentieth century, physicists had a dim glimmering of this. But not until time travel came to be did the fact of it stab into human lives.

  If you have gone into the past, you have made it your present. You have the same free will as always. You have laid no special constraints on yourself. Inevitably, you influence what happens.

  Ordinarily the effects are slight. It’s as if the space-time continuum were like a mesh of tough rubber bands, restoring its configuration after it’s felt some disturbing force. Indeed, ordinarily you are a part of that past. There really was a man who traveled with Pizarro and called himself Brother Tanaquil. That was “always” true, and the fact that he wasn’t born in that century, but long afterward, is incidental. If he does minor anachronistic things, they don’t matter; they may excite comment, but memory of them will die out. It’s a philosophical question whether or not reality keeps flickering through such insignificant changes.

  Some acts, though, do make a difference. What if a lunatic went back to the fifth century and provided Attila the Hun with machine guns? That kind of thing is so obvious it’s fairly easy to guard against. But subtler changes— The Bolshevik Revolution of 1917 came near failing. Only the energy and genius of Lenin pulled it through. What if you traveled to the nineteenth century and quietly, harmlessly prevented Lenin’s parents from ever meeting each other? Whatever else the Russian Empire later became, it would not be the Soviet Union and the consequences of that would pervade all history afterward. You, pastward of the change, would still be there; but returning futureward, you’d find a totally different world, a world in which you yourself were probably never born. You’d exist, but as an effect without a cause, thrown up into existence by that anarchy which is at its foundation.

  When the first time machine had been built, the Danellians appeared, the superhumans who inhabit the remote future. They ordained the rules of time traffic and established the Patrol to enforce these. Like other police, we mostly assist people on their lawful occasions; we get them out of tight spots when we can; we give what help and kindness we dare to the victims of history. But always our basic mission is to protect and preserve that history, because it is what shall finally bring forth the glorious Danellians.

  “I’m sorry,” Helen Tamberly said. “That was idiotic of me. But I’ve been…so worried. Stephen was only supposed to be gone three days. Six years for him, three days for me. He wanted that much time merely to reaccustom himself to this milieu. He meant to wander about incognito, getting back into Victorian habits, so he wouldn’t absent-mindedly do something that would surprise the servants or our local friends. It’s been a week!” She bit her lip. “Forgive me. I’m still babbling, am I not?”

  “Far from it.” Everard took forth pipe and tobacco pouch. He wanted that small comfort in the face of this anguish. “Loving couples like you make a bachelor like me feel wistful. But let’s get down to business. Best for us both. You’re native to England of this century, aren’t you?”

  She nodded. “Born in Cambridge, 1856. I was orphaned at seventeen, left with modest independent means, studied classics, became rather a bluestocking, eventually was recruited into the Patrol. Stephen and I met at the Academy. In spite of the age difference—which doesn’t matter for us, thank God—we…hit it off, and married after we graduated. He didn’t think I would like his birthtime.” She grimaced. “I visited it, and he was right. For his part, he felt—feels happy here and now. His persona is that of an American employee of the import firm. When I go off to my own work, or bring some home with me, well, it is unusual for a woman to have scholarly interests, but not extraordinary. Marie Sklodowska—Madame Curie—will enroll in the Sorbonne just a few years hence.”

  “And people in this milieu are better at minding their own affairs than they are in mine.” Everard occupied himself with tamping his briar full. “Uh, I daresay you two do more things together than is common for man and wife these days.”

  “Oh, yes.” Her eagerness was pathetic to hear. “Beginning with our holidays, in this era and that. We fell quite in love with archaic Japan, and have been back several times.” Everard concluded that that was a country isolated enough, with a population small and unsophisticated enough, illiterate, that the Patrol allowed occasional visits by blatant outsiders. “We’ve taken up handicrafts; pottery, for example; that ashtray beside you is his work—” Her voice died away.

  Hastily, he queried onward. “Your field is ancient Greece?” The man who met him at the base hadn’t been sure.

  “The Ionian colonies, chiefly in the seventh and sixth centuries before Christ.” She sighed. “It’s ironic that there the Patrol cannot admit me, a Nordic woman.” She tried to rally. “But as I said, we’ve seen much else that is wonderful.” Suitably outfitted, carefully guided. “No, I mustn’t complain.” The stoicism cracked. “If Stephen—if you do bring him back—do you think he can be persuaded to settle down and do research in place, like me?”

  Everard’s match cast a loud scrit across the silence that followed. He rolled smoke over his tongue and cradled the rough wood in his hand. “Don’t count on it,” he said. “Besides, good field historians are scarce. Good people of every kind are. You may not be fully aware of how undermanned we are in the corps. Your sort make it possible for his sort to operate. And mine. Normally we came home safe.”

  Patrol work was anything but bravado and derring-do. It depended on exact knowledge. Agents like Steve collected most of that on the spot, but they too required the patient labor of those like Helen, who collated the reports. Thus, observers in Ionia brought back immensely more information than those chronicles and relics that survived into the nineteenth century had ever contained; but they could not do her job, which was to put it all together, interpret, arrange, and prepare briefings for the next expeditions.

  “Someday he must find something safer.” She blushed. “I refuse to start a family until he does.”