7: Chapter 7 Time Assassin

On Earth, time was carved into fragments.

Forty minutes of class, ten minutes of break.

Every segment of time had its purpose, and the moment the bell rang, one had to switch gears.

But the Wasteland had no countdowns.

In this world stripped bare of its civilized coat, the passage of time had lost all reference metrics.

There was no morning rush starting at sunrise, nor any class bell ringing on the dot.

Only the dark-red sun and the matching-colored moon in the sky alternated in gazing down at this desolate land like a pair of bloodshot eyes.

Time here was continuous, complete, and belonged solely to him.

He studied, stopping for a sip of water or a bite of compressed biscuit when tired, then standing up to walk a couple of laps outside the tent.

There was no need to check a watch or rush his progress; his body would tell him when to rest and when to keep going.

In short.

On this Wasteland, he had nothing else to do.

All he needed to do was survive, study, and solve practice problems.

The survival part was already fully secured outside the tent.

Twenty liters of water, forty catties of compressed biscuits, a tent, a sleeping bag, and an entrenching shovel.

The studying and problem-solving part lay right in front of him.

Five thousand sheets of A4 paper, two hundred pen refills, and a phone stuffed with textbooks and real exam papers.

Since there was still over half a year until the Gaokao and he would most likely be able to enter once a month, there was absolutely no need for him to try and accomplish everything in one go.

A steady stream flows far; taking slow, firm steps was the strategy with the highest winning odds.

When sleepy, he slept.

When day broke, he woke up naturally.

Grabbing the entrenching shovel, he went off to relieve himself.

The Wasteland in the morning was much colder than in the afternoon.

He put on his military coat and squatted at the tent entrance to eat compressed biscuits.

They were pale yellow, packed tightly, with cross-shaped indentations on the surface.

He took a bite.

Heavily salted, oily, and hard as a brick.

He chewed very slowly, swallowing each mouthful only after it was completely ground into a paste.

It took him nearly five minutes to chew a single biscuit.

Then, unscrewing the cap of the water jug, he washed down two multivitamin tablets with mineral water.

The pills had a slightly sour, chemical taste.

The water was frigid, so cold that he could feel the outline of his esophagus as he swallowed.

After finishing breakfast, he glanced at the bottle of treated water that had been left to settle overnight.

The sediment had completely settled at the bottom, leaving roughly the upper four-fifths of the liquid fairly clear with a pale yellow tint.

At the bottom was a layer of grayish-white sediment, about one centimeter thick.

But Jiang Lin decided to wait until the mineral water actually ran out before deciding whether to drink it.

A new day. Time to carry on.

In the morning, he worked on mathematics—analytic geometry.

Rather than attempting new problems, he re-did the ones he had gotten wrong in the Real World.

He had an error notebook in the Real World containing all the mistakes from his exams and homework over the past two months.

Before crossing over, he had snapped photos of the notebook pages with his phone, and now he worked through them one by one based on the pictures.

The first problem was an ellipse question from a midterm exam.

Eccentricity, line-ellipse intersection, finding chord length.

When he solved this in the Real World, he wrote the wrong sign on the third step, making everything after wrong and forfeiting all twelve points.

He set up points anew, set up simultaneous equations, applied Vieta's formulas, and used the chord length formula.

Step by step, he derived downwards. When he reached the third step, he paused.

Right here—last time, he had flipped the plus and minus signs.

This time he wrote very slowly, verifying the signs at every step.

After finishing, he checked the answer sheet; it was correct.

He rewrote the formulas used for this problem from memory on the margin of the scratch paper.

Standard equation of an ellipse, eccentricity formula, chord length formula.

After writing them down once, he recited and wrote them from memory again.

The second was from another monthly exam.

Hyperbola—finding the asymptote equations and eccentricity.

Back then, he had no idea how to solve it and turned in a blank answer.

Now, he first recalled the basic properties of hyperbolas from the textbook.

The two forms of the standard equation, positions of the real and imaginary axes, and the asymptote formula.

Then he worked through it step by step. He managed to solve it, but got stuck for a long time in the middle, unable to remember whether the slope of the asymptote was b over a.

Only after checking the textbook PDF on his phone did he confirm it.

He wrote out the hyperbola asymptote formula five times on the margin of his scratch paper.

Five times.

In the past, he would have considered this a waste of time, only to get stuck again on the next exam.

That was just the kind of person he was.

It wasn't that he didn't try hard; his mind was just slow at memorization.

What others could memorize after writing twice took him five, eight, or ten times.

The third problem was about parabolas.

Finding focus coordinates and directrix equations.

He had gotten this one right previously, but it took too long.

During the exam, spending nearly ten minutes on this single multiple-choice question left him with insufficient time for the comprehensive questions.

He re-did it once, then started thinking: was there a faster method?

He listed all four standard equations of a parabola, annotating each with its focus coordinates, directrix equation, and opening direction.

Then he compared them with the problem to see if he could spot the answer at a glance.

His conclusion: if he could memorize the geometric significance of 'p' in the parabola equation—the distance from the focus to the directrix—he could save time on derivation.

He circled the geometric meaning of 'p' in red pen and drew a five-pointed star next to it.

Three problems took an entire morning.

In the Real World, how many problems could one do in a morning?

At least thirty or forty.

The test papers distributed by teachers had a forty-minute time limit for over a dozen analytic geometry problems, collected as soon as time was up.

Every time, he barely finished, but got more wrong than right.

Because it was rushed, leaving no time to think.

Now, spending a whole morning, he solved only three problems.

For each one, he rewrote it repeatedly, recited formulas from memory, and pondered the 'why' over and over.

Appallingly slow.

Yet he could feel the concepts in these three problems taking deep root in his mind.

In the afternoon, he studied Physics.

Still electromagnetic induction, application problems on lenzs law.

He had saved a thematic exercise set on electromagnetic induction on his phone—a digital copy provided by the school with twenty multiple-choice questions in total.

He started on the first one.

Inserting the N-pole of a magnet into a coil, asking for the direction of the induced current.

He pulled up the 'rebellious coil' diagram he had drawn yesterday in his head: insertion -> magnetic flux increases -> induced magnetic field opposes -> Right-hand rule -> counterclockwise.

Select C.

The second problem.

A conductive rod cutting magnetic field lines on rails, asking for the direction of induced current and Ampère force.

Cutting magnetic lines creates motional electromotive force: Right-hand rule determines current, Left-hand rule determines Ampère force.

First, he extended his right hand, thumb pointing in the direction of motion, four fingers pointing toward the current direction.

Then he switched to his left hand, four fingers pointing in the current direction, magnetic field passing through the palm, thumb pointing in the direction of the Ampère force.

Switching between the two rules back and forth, he stumbled through the process and even mixed up his right and left hands once.

After finishing, he wrote a line on the scratch paper: "Right hand generates power, left hand receives force. Right generates, left receives."

He circled it with a red pen.

Third problem, fourth, fifth.

After completing each problem, whether right or wrong, he retraced the analysis process of lenzs law from start to finish.

Did the magnetic flux increase or decrease?

Was the induced magnetic field in the same or opposite direction?

Which direction was the current flowing?

By the tenth problem, he noticed he no longer needed to start from the 'rebellious coil' diagram every time.

Upon reading the physical scenario described in the question, the direction of magnetic flux change instantly popped into his head, followed by the direction of the induced magnetic field, and then the current direction.

The sequence was becoming second nature.

But it was still very slow.

For a single multiple-choice question, from reading to selecting the answer, took him three to four minutes.

During exams, comprehensive science multiple-choice questions allowed an average of only about two minutes each; at his current pace, he would never finish in time.

No matter.

Get it right first, then worry about speed.

He spent an entire afternoon plus half the night on those twenty multiple-choice questions.

Four were incorrect.

Two mistakes were due to reversing the direction in lenzs law, one was confusing motional and induced electromotive forces, and one was a pure calculation error.

He re-did the four incorrect problems with a red pen, marking the reasoning beside each step.

This step used Faraday's law, this step used the Right-hand rule, this step used the Left-hand rule.

After marking them, he re-read the knowledge points corresponding to the four missed questions in the textbook PDF.

After dark, he ate his second compressed biscuit, drank a few gulps of water, and began memorizing English vocabulary.

Twenty words, starting from 'A' in the Gaokao vocabulary list.

abandon, to give up.

ability, capacity.

aboard, on board.

abroad, overseas.

absence, state of being away.

...

For every word memorized, he copied it three times on scratch paper.

On the first copy, he looked at the word and its definition, pronouncing it aloud.

On the second copy, he covered the Chinese, looking at the word to say its meaning.

On the third copy, he constructed the simplest possible sentence using the word.

Memorizing twenty words took nearly an hour.

He closed his phone, flipped the scratch paper over, and wrote them down from memory.

He got three wrong.

He missed an 'i' in 'ability', mixed up 'abroad' and 'aboard', and remembered 'absence' as its antonym.

He circled the three mistakes with a red pen, recopying them and making new sentences.

Then he stood up, walked out of the tent, and paced back and forth in front of the broken wall for five minutes.

Cold wind rushed down his collar, making him hunch his neck from the chill, but his mind grew clearer.

Returning to the tent five minutes later, he wrote them out from memory again—all correct.

One day, twenty words.

At this speed, he could memorize six hundred words in thirty days.

Still, with three thousand five hundred words in the Gaokao vocabulary list, six hundred was just a fraction.

And so, the second day passed.

The third day, the fourth day, the fifth day...

Days settled into an extremely disciplined routine.

Dawn broke, the phone timer rang, and he woke up.

Put on coat, grab shovel, walk fifty meters to the pit in the low hollow to relieve himself, shovel dirt over it, and walk back.

Eat compressed biscuits, drink mineral water.

Then crawl into the tent to start solving problems.

Math in the morning, Physics in the afternoon, and while it was still daylight in the evening, read Chemistry or Biology.

Subjects that didn't require heavy calculations could be read by daylight at the tent opening, saving battery power on the camping lantern.

After dark, turn on the light, continue unfinished problems, or memorize English vocabulary.

Eighth day, ninth day, tenth day.

The first pack of scratch paper was used up—one thousand sheets—and five ballpoint pen refills were replaced.

Roughly nine catties of compressed biscuits were consumed; the second jug of mineral water was finished, and he started on the third.

The twelfth day.

He worked on a final, challenging function derivative problem.

The final problem of the 2019 National Examination Science Math paper: discuss monotonicity, prove an inequality.

He solved the first sub-question: take the derivative, analyze case by case.

He got stuck on the second sub-question.

Prove that when x > 0, e^x > x^2.

He stared at the problem statement for over ten minutes, writing three or four lines on scratch paper only to cross them out.

He flipped through the textbook, reading the chapter on derivative applications, then reviewing the properties of exponential functions.

Finally, he found a hint in an example problem in the textbook.

e^x ≥ x + 1, with equality holding if and only if x = 0.

This was a fundamental inequality of exponential functions.

He tried substituting using this inequality; it didn't work the first two times, but succeeded on the third.

Proof complete.

After finishing, he put the problem away and wrote a line on the edge of the scratch paper: "Exponential inequality: e^x ≥ x + 1. Think of this first when seeing e^x."

Then he circled the line in red pen.

The thirteenth day.

About twelve catties of compressed biscuits had been eaten, and half of the third jug of mineral water was gone.

Time was a strange thing on the Wasteland.

It passed very slowly.

Every minute was a full sixty seconds, every second genuinely flowing through his consciousness.

Yet at the same time, it passed very quickly.

So quickly that fifteen days felt like an instant.

Because every day, he did roughly the same things.

Wake up, eat, solve problems, eat, solve problems, dark, sleep.

No weekends, no class breaks, no unexpected events to disrupt his rhythm.

The days flowed past smoothly, like a river without stones.

He discovered that within this rhythm, he had become extraordinarily calm.

[part:gemini-3.5-flash-lite]

The tasks of every day were clear, and the methods were clear; all he needed to do was execute them.

He didn't need to make choices.

He didn't need to worry about rankings.

He didn't need to pretend not to care every time the score report was handed out, folding it up and stuffing it into his mistake notebook.

Here, his only reference point was the problems he had solved yesterday, and whether he could solve them today in a shorter time and with a better method.

The twentieth day.

Twenty days.

He had stayed in this world without a second living person for twenty days.

Four hundred and eighty hours.

Twenty-eight thousand eight hundred minutes.

If following the normal time flow rate, what time was it in the Real World now?

It was probably around two in the afternoon.

Mom should be working in the supermarket, standing behind the cashier counter, scanning barcodes, collecting money, giving change, and saying to every customer, "Hello, welcome back next time."

Dad should be sleeping.

Seatmate Sun Ming must be secretly rubbing the glass and playing Honor of Kings.

...

Everyone was living through an ordinary December fourth.

No one knew that he, Jiang Lin, had already spent twenty sunrises and sunsets alone on another timeline.

This hidden sense of dislocation gave Jiang Lin a very strange emotion.

It wasn't loneliness.

On the Wasteland, he truly had no one to talk to, but he didn't feel lonely.

When solving problems, his mind was full of formulas and numbers, leaving no extra space to feel lonely.

When resting, he would sit at the entrance of the tent and look at that eternally unchanged dark red Wasteland.

After looking at it for a long time, that Wasteland didn't feel desolate anymore.

It was just there.

Like a silent problem.

It didn't need to be understood, only observed.

The emotion he generated was closer to a sense of privilege.

Not the kind of condescending sense of privilege.

It was the kind of privilege where the whole class was writing the same test paper in the same classroom, and only he was allowed to take the test paper home and write it slowly with more time than others.

He knew this was unfair.

But the college entrance examination was never fair.

Some people had exceptionally good brains, some people had rich families to hire one-on-one tutors, and some people were born in provinces with less pressure for college entrance examination competition.

This world was never fair.

He had just accidentally obtained a little unfair advantage that belonged to him.

What he needed to do wasn't to feel guilty, but to push this little advantage to its absolute limit.

The twenty-first day.

The mineral water was finished.

There was only more than half a bucket of treated light yellowish-white liquid left in the tent.

Jiang Lin picked it up, unscrewed the cap, and leaned close to sniff it.

The sour taste was already very faint, replaced by an astringency unique to mineral salts and a very faint odor similar to swimming pool disinfectant.

The liquid surface was calm, with a thin layer of grayish-white sediment at the bottom.

About four-fifths of the upper layer was clear, with a color between light yellow and transparent.

He poured out a small cup.

Using the cap of the water bucket, it was a shallow layer at the bottom of the cup, which he raised to his eyes and looked at against the light of the camping lamp.

Clear.

No suspended solids.

He brought the cup to his mouth, his whole body tensing up, and took a sip.

The moment the liquid touched the tip of his tongue, there was no sharp pain of being burned like last time.

It was just a very complex taste.

First was sourness.

The kind of sourness after lemonade had been left out for a whole day.

Then was astringency.

The surface of the tongue felt like it was covered by an extremely thin film, and saliva was secreted more than usual.

Next was saltiness.

Not the saltiness of table salt, but a sharper mineral saltiness, like licking a stone.

Finally was bitterness.

The bitterness lingered at the root of his tongue and was still there after swallowing.

He held this mouthful of liquid in his mouth to savor it for a long time, then swallowed it.

His esophagus had no burning sensation.

His stomach didn't churn either.

He waited for ten minutes.

No nausea, no abdominal pain, no dizziness.

He waited another half hour.

Everything was normal.

It could be drunk.

It didn't taste good, but it was drinkable.

It could make him live many more days on this Wasteland.

From the twenty-first day to the twenty-fourth day.

The third pack of draft paper was used up, and the pen refill was changed to the 50th one. A thin layer of callus had worn on the side of his middle finger, a bit thicker than before time-traveling.

The twenty-fifth day.

At night, the wind suddenly became very strong. One of the ground pegs loosened, and the outer tent was blown to flap loudly, waking him up.

Wrapped in a military overcoat, he rushed out to press stones down again, getting covered in dust from the wind and eating a mouthful of gravel.

Coming back and wrapping himself in the sleeping bag, he suddenly realized that he hadn't heard a second person speak for a long time.

The twenty-sixth day.

The treated water was also about to be finished.

Without water to drink, life couldn't go on.

The thought of returning floated into his mind, but around dusk that day, he encountered the first rain since coming to the Wasteland.

At that time, he was squatting at the tent entrance reading a chemistry textbook, when he suddenly felt a coolness on his face.

Raising his head, a drop of water fell on his forehead.

Then the second drop, the third drop, connecting into lines, weaving into a net.

The rain on the Wasteland wasn't the transparent kind on Earth.

In the dark red sky light, the rain threads presented an extremely faint grayish-yellow, drawing into slanted fine lines as they fell.

He reached out his hand to catch a few drops and leaned in to sniff them.

There was a very faint sour smell.

He quickly took the empty mineral water bucket out of the tent and placed it in the low-lying area at the tent entrance.

He didn't have a suitable water collection container, but rainwater was water itself.

Even if the acidity was slightly high, it was ten thousand times cleaner than the grayish-black liquid in that puddle.

Five buckets were placed side by side outside the tent. The rain threads fell in slanted, creating dense ripples on the water surface.

A shallow layer of grayish-yellow liquid quickly accumulated at the bottom of the buckets.

It rained for about an hour.

The wind wrapped the rain threads and drifted into the tent entrance. He zipped up the outer tent and looked at the rain outside through the gauze net.

The rain fell on the dark red soil, and the color of the ground deepened, turning from rusty color to dark brown close to black.

The sulfur smell in the air was suppressed a bit by the rainwater.

After the rain stopped, he concentrated the grayish-yellow rainwater into two buckets.

There were about 10 liters.

He took out pH test paper, dropped a little rainwater on it, and compared it with the color chart. The pH was roughly between 4.5 and 5.0.

Lemon juice had a pH of about 2 to 3, and vinegar was around 3.

4.5 to 5.0 was equivalent to water with a small amount of lemon juice added, and the acidity wasn't high.

He poured this cup of rainwater into a newly made simple filtration device.

Filter paper, absorbent cotton, activated carbon, fine sand.

The color of the filtered liquid changed from grayish-yellow to nearly transparent, with only an extremely faint rice-white.

Then he added a small amount of baking soda to neutralize the acidity.

Bubbles hissed for a while, much less than when treating the puddle liquid last time.

After standing and settling, the liquid became clear.

He measured the pH, which was around 6.5, close to neutral.

It could be drunk.

Looking at these two buckets of treated rainwater, Jiang Lin suddenly felt that this rain came at just the right time.

Then he did something he had always wanted to do but thought was a waste of time.

He found all the original texts for the classical Chinese reading of the National Examination papers from the past five years and read them one by one.

Not doing problems.

Just reading.

Reading them like stories.

He used to be most afraid of classical Chinese reading.

Because he couldn't understand it.

He knew every single word, but once connected into a sentence, he didn't know what it was talking about.

The teacher said it was insufficient accumulation.

But accumulation required time.

What he lacked was time.

Now he had time.

The first piece he read was the biography of Sunshu Ao from "Records of the Grand Historian: Biographies of Upright Officials".

With hundreds of words, he read it for almost an hour.

He clicked on the phone dictionary to check every unfamiliar word.

He checked the translation for every sentence pattern he couldn't figure out.

The twenty-seventh day.

He reviewed all the mistake problems he had done after coming to the Wasteland.

Mathematics analytic geometry and function derivatives, Physics electromagnetic induction, chemistry industrial processes, biology genetics problems.

Beside every mistake problem was the reason for the mistake and the correct solution written by him in red pen.

He covered the solution and redid the mistake problem.

Most of them could be done correctly.

A small portion still got stuck.

For the stuck problems, he wrote them out again with a blue pen on the side, folded a corner, and looked at them tomorrow.

The twenty-eighth day.

He redid those folded-corner problems.

There were still two problems that were stuck.

One was a Physics electromagnetic induction two-rod problem; the scenario was too complex, with two rods moving on guide rails at different speeds, and he couldn't figure out how to draw the equivalent circuit.

Another was a mathematics function derivative proving inequality problem, which used a scaling technique he had never seen before, scaling e^x to a quadratic function. The train of thought was too a leap, and he couldn't think of it.

For these two problems, he wrote a single character next to them in red pen: "Ask."

Ask the teacher after going back.

He used to never ask the teacher questions.

It wasn't that he didn't have questions, but that he didn't dare.

He was afraid the teacher would think he didn't even know such simple problems.

Now he dared.

Because he knew he had truly thought about it seriously, for a very long time, and many times, and he really couldn't think of it.

It wasn't laziness; his brain just couldn't make that turn.

The twenty-eighth day.

There was still a small half-bucket of compressed biscuits.

Two pieces a day, one each in the morning and evening.

The calories were enough, but he began to miss Mom's stir-fried tomatoes with eggs.

The tomatoes had to be stir-fried until juice came out, the eggs had to be tender, salt shouldn't be added too much, and a tiny bit of white sugar should be sprinkled at the end to enhance the umami.

Served with a bowl of white rice, mixing the tomato juice into the rice, one bite could wipe out half a bowl.

He licked his lips.

After going back, his first meal had to be this.

The thirty-third day.

When memorizing words at night, his brain suddenly mistook abroad for broadcasting, recalled the sound of the classroom broadcast, and froze for a moment.

The forty-second day.

Jiang Lin swallowed the last bite of compressed biscuits.

There was still a little water left, but unexpectedly, the compressed biscuits were finished first.

The forty-third day.

Jiang Lin didn't do new problems.

He organized all more than 3,000 sheets of draft paper used up in these forty-two days.

Classified by subject, sorted by time, and tied into four piles with nylon rope.

One pile for mathematics, one pile for Physics, one pile for chemistry and biology, and one pile for English and miscellaneous.

Every pile contained every detouring road he had walked in these forty-two days, every shortcut he discovered, and every bridge he built.

He squatted at the tent entrance, looking at these four piles of draft paper.

More than 3,000 sheets of paper.

Nearly 5,000 pages.

Every single page was filled with writing.

This was all his savings on the Wasteland.

It was something he saved bit by bit on another timeline.

He didn't intend to take it back.

The campsite wasn't moved either, letting it maintain the appearance of these past few days.

He only shouldered a duffel bag stuffed with two woven snake-skin bags.

"Return!"

When this intense thought rose to the peak in his mind, his vision went black.

The weightless sensation passed in a flash.

When Jiang Lin opened his eyes again, the warm yellow light of the desk lamp gently hit his face.

He was still standing right in the center of his bedroom, maintaining the posture before returning.

Looking at the alarm clock on the desk again.

He was astonished to find that it was actually six-o-one in the early morning.

The first time he was teleported to the Wasteland, he stayed for about thirty-six hours.

This time, being teleported to the Wasteland for the second time, he stayed for forty-two days.

Unexpectedly, on this side, only one minute had passed.

Judging by this, no matter how long he stayed in the Wasteland World, it was very likely that only one minute had passed on this side.

"Jiang Lin, are you up?"

Mom's call came from outside the door, just like usual.

But the moment he heard this voice, Jiang Lin's eye sockets instantly turned completely red.

The grievances, fear, and longing accumulated at the bottom of his heart for more than forty days were like a breached flood at this moment.

"I'm up."

Suppressing his crying voice, Jiang Lin wiped away his tears and responded.