Guth Bandar skirted the fighting around the temple of the war god, took a right turn off the processional way and descended the cramped, winding street that connected the acropolis with the cattle market. He ignored the shrieks around him and the whiff of acrid smoke stealing up from the lower town, where the invaders were firing houses they had already looted.

After a few paces he found the narrow alley and stepped into its dark confines. The passage led to the blank stone wall of a substantial house where a man in the robes of a prosperous merchant was scraping a hole beneath the masonry. Beside him was a leaden coffer. As Bandar squeezed past, the man finished digging. He opened the box long enough to strip rings from his hands and a chain from his neck and place them within. Polished gold and the glint of gems gleamed in the dim light then the lid snapped shut.

Bandar paid no heed. The merchant was always here at this point in the cycle. In a moment he would scuttle back to the street, there to be caught by a clutch of soldiers, iron swords out and bronze corselets crimson with blood and wine. They would torture the merchant with practiced skill until he led them, weeping and limping, back to the buried hoard. Then they would cut his throat and throw him on the rubbish heaped against the wall at the alley’s end.

Now the man stood and turned to go. He passed Bandar as if he were not there, which from the merchant’s point of view, he was not. Bandar continued to chant the nine descending tones, followed by three rising notes, which insulated him from the man’s perceptions as it did from those of all the idiomatic entities intrinsic to this Event.

The chant was called a thran, one of several dozen specific combinations of sounds which enabled scholars of the Institute of Historical Inquiry, where Bandar was apprenticed, to sojourn among the multitude of archetypal Events, Landscapes and Situations which constituted the human noösphere — what the laity called the collective unconscious — of Old Earth.

Still chanting, Bandar climbed the stinking heap at the end of the alley. At its apex would lie a large amphora with a fractured handle. He would seize the amphora, prop it against the wall, then mount and scramble atop the barrier. There he would chant a new thran, opening the gate to the next-to-last stage of the test: a Landscape preserving an antique time when the world was mostly forest.

The apprentice had already made his way by rocket-tube and teeming public slideways across the world-girdling City of a hyperindustrialized global state that flourished and faded eons before, taken a short detour through an insidious alien invasion — it had failed — and traversed a rift valley where early human variants competed to determine whose gene pools would dry to dust in the evolutionary sun. Now a walk in the forest and a segue into one of the Blessed Isles would see his quest completed.

But when he reached the top of the refuse heap, instead of the great urn he found it smashed to fragments. That ought to have been impossible, Bandar knew; nothing changed in the noösphere. Events and Situations repeated themselves exactly and eternally.

There was only one possible explanation: Didrick Gabbris had already passed this way, climbed on the amphora and departed. But before doing so he had contrived to destroy the vital stepping stone.

Frantic, Bandar scoured the area, digging through the rubbish in hope of finding something of sufficient size and sturdiness to take his weight. But if there had been anything useful, Gabbris had removed it.

Bandar was left with three choices. His first option was to search the city and bring back something else to climb on. But his insulation from the idiomats’ perceptions would not extend to a substantial object that was inherent to the Location. And the longer he interacted closely with the substance of the Location, the more risk that the thran’s effect would weaken and he might be perceived.

Suppose some brutal soldier, startled as a chair was borne along by a vague, misty figure, thrust his spear into the mist. Bandar’s corpse would thence forward be a permanent feature of the Sack of the City. His tutors had warned of the risks of “dying” in an Event. The sojourner’s consciousness became bound to the Location, reforming as one of the idiomatic entities and forever “living” and “dying” as the cycle played out endlessly.

His corporeal body, seated cross-legged on a pad in the examinations room at the Institute, would remain comatose. It would be transferred to the infirmary, bedded and intubated, and consigned to a slow decline.

Bandar’s second option was to find an out-of-the-way corner and remain there until the Event concluded and began anew. Then, when he came back to the rubbish heap, the amphora would be waiting for him. But that would take time — too much time, even though durations in the noösphere did not run at the same speed as in the phenomenal world.

Different sites had their own internal clocks. This Event ran far slower than reality; the few hours in which he waited out the cycle would be almost a day in the examination room. Bandar would be the last apprentice to complete the quest; he could abandon all hope of winning the Colquhoon Bursary and being admitted to the advanced collegia.

Which was exactly why Didrick Gabbris had smashed the urn. Gabbris would win the bursary. Gabbris would scale the academic heights, while Guth Bandar slunk back to his family’s commerciant firm, to spend his life buying and selling and fretting over the margins between the two.

His third option was no help: he could intone a specific thran and a ripple would appear in the virtual air. He would step through the emergency exit and instantly plunge back into his own seated body. He might complain to the Institute’s provost about Gabbris’s perfidy, but by the time a board could be convened to investigate, the Event would have recycled and all evidence of the crime would have disappeared.

Glumly, Bandar weighed his options and decided to risk searching for a step-up. But as he started down the pile of refuse there was a commotion at the mouth of the alley and three soldiers appeared, pushing the merchant before them. They watched as he knelt and dug up the box, amid coarse jokes and pokes with a sword at the man’s plump buttocks.

There was nothing Bandar could do. The way was too narrow for him to pass, even unseen. He must sit on the rubbish heap and sing the thran, waiting while the soldiers gloated over the treasure, argued over its division, then cut the merchant’s throat and finally departed.

There would be no time to find something to step on. Sadly Bandar waited for the blood to spurt and the soldiers to leave. He would open a gate and return to the examination room. Perhaps his story would be believed and he would be given a make-up exam. But that was a faint hope; he could imagine the conversation.

Bandar would say, “I accuse Didrick Gabbris of malfeasance in the matter of the amphora.”

Gabbris would not deign to sully a glance by directing it at Bandar. He would elevate his nose and say, “Words without substance fleetly fly but seldom stick. Bring forth your evidence.”

“I have none but my character.”

“Your character is a subjective quality. You perhaps measure it as large and splendorous, while others might call it mean and marred by envy.”

“This is injustice!”

“Again, a subjective concept, while blunt facts resist manipulation. Failure must find no favor.”

Senior Tutor Eldred would tug at his sparse side whiskers and make his disposition. He would be swayed by the force of Gabbris’s views. Bandar’s would seem the squeakings of some timorous creature.

The pathetic scene at the foot of the refuse heap was nearing its conclusion. The merchant said, as always, “There, you have taken all that I valued.”

One of the soldiers drew a dirk. “Not quite all.”

The merchant trembled. “My life is of no worth to you. Though you take it from me you cannot carry it away with you.”

“Yet we are inclined to be thorough,” said the invader.

Bandar waited. He thought of some of the Locations he had visited during his years at the Institute, the places he would miss. It was then, as he said goodbye to some of his favorites, that it occurred to him that he had a fourth option.

The Institute had issued the examination candidates a partial map of the noösphere, showing only the Locations they would need to navigate the test course. The full chart of humanity’s collective unconscious was an intricately convoluted sphere, complexity upon complexity. It was the work of thousands of years of exploration by noönauts, many of whom had been absorbed by perils lurking in dark corners of the Commons.

Bandar did not have such a map. A noönaut could take on his journey only what he could hold in his memory, and to encompass the schematic representation of an organic realm that had been evolving for eons was itself a work of years.

But there was a physical representation of the full map in the communal study chamber and Bandar had spent many hours gazing into its labyrinthine depths. He could not reify it fully like a master, so that it would appear to hang in the air before him, twisting and rotating to display its maze of lines and spheres. But he could recall large parts of it, all of the major Landscapes, most of the first-order Situations and more than a few of the significant Events.

The more he thought of it, the clearer grew his recollection of the map. He saw connections and linkages from this Event to a Landscape and from there to a Location from which he knew three paths radiated. In his mind’s eye he could plot a route that would let him navigate to the test’s final Location, a prototypical island paradise, where Eldred waited for the candidates to arrive.

It was just possible that Bandar could indeed find his way home. Better yet, he was fairly sure that some of the sites through which he would travel had advantageous temporal dimensions: the alternate route, though it required more steps, might actually be traversed in less objective time than the course the tutors had set.

The merchant had gurgled out his last bloody breath. The alley lay empty. Bandar made up his mind to try the long way home. Perhaps his resourcefulness would so impress the examiners that they would overlook his failure to follow the prescribed course. At the worst, if hopelessly stuck, he could exit through open an emergency gate.

He risks nothing who has lost all, he told himself. Singing the thran, he returned to the processional way and followed it past the burning royal palace to the city’s shattered gates. Dead defenders were piled high and he had to climb a rampart of bodies to reach the wooden bridge that spanned the canal.

A little beyond was a stand of date trees. A single attacker, pinned to a trunk by an arrow through his shoulder, weakly struggled to work the head free of the wood. His eyes widened when Bandar ceased intoning the insulating thran and suddenly appeared before him.