抓抓猫与末日地堡 Zhuazhua Cat and the Doomsday Bunker

After struggling through three winding and narrow corridors, a little robot cat tumbled and rolled into the study of the underground bunker. It was a robot cat with a yellow metal shell, a square head, a square body, and flexible jointed limbs. Its two big round eyes were like searchlights—in fact, their detection power was far stronger than any searchlight. But at this moment, those eyes had lost their usual sparkle and were empty and dull. This robot cat was named Zhuazhua. When it crashed and fell with a clatter onto the study floor, its owner Song Mingming was studying a three-dimensional holographic map floating in mid-air. The noise Zhuazhua cat made truly startled her. Song Mingming was a fourteen-year-old girl with a pale face and a slender figure. Her phoenix eyes shone like polished lacquer, and her hair was tied in a ponytail at the back. She looked fragile, yet she was clever and quick-witted. Half a year earlier, a chain of nuclear explosions lasting three days had destroyed most of the Earth. Only those with foresight who had fled in time into pre-built doomsday bunkers had survived. Song Mingming and Zhuazhua cat were among them. “Zhuazhua!” Song Mingming looked at the cat lying sprawled on the floor and frowned. “What’s wrong with you?” Zhuazhua cat made no sound and did not move, just like a dead cat… or, to be precise, just like a dead robot cat. Song Mingming sensed something was wrong and hurried over to check. She saw that Zhuazhua’s battery was already in the red warning state and could shut down at any moment. One of its arms had been dislocated from the shoulder and was connected only by a few extremely thin steel wires. Its metal shell was covered with many shallow dents caused by hard impacts. Song Mingming drew in a sharp breath. Zhuazhua had been carrying out ground detection missions for a full month. This was the first time it had returned injured. She immediately ran to drag over the charging station and plugged Zhuazhua in. Then she fetched her toolbox and carefully examined its wounds. While doing all this, her heart pounded wildly, but luckily she possessed an inborn ability to stay calm in crisis. The more nervous she felt, the more she forced herself to remain steady and handle things in an orderly way. One minute of fast charging was enough to restore Zhuazhua’s basic functions. Song Mingming then pressed the memory playback button and quickly reviewed its experiences of the day to find out how it had been hurt. Zhuazhua’s sights and sounds from that day projected into the air, just like playing a first-person movie. First appeared a little alarm clock running all over the place, along with Zhuazhua’s panting breaths and the clattering sounds of bumps and crashes. Every morning for Zhuazhua began with chasing this alarm clock. Only by catching it could the annoying ringing be turned off. After the alarm was silenced, the yawning and eye-rubbing Song Mingming appeared before Zhuazhua’s eyes. She mumbled, “Zhuazhua, it took you five minutes to catch the alarm today.” Zhuazhua answered in its soft, childish voice, “Mew! No matter how many minutes it takes, catching the alarm means I’m a good cat!—Is there silver-fish jerky for breakfast today?” Song Mingming tapped Zhuazhua’s forehead with her index finger. “You greedy little cat! Of course there is! Today’s work will be hard, so you must eat more!” The silver-fish jerky that Zhuazhua loved most was actually energy blocks—high-powered batteries. Song Mingming’s father had been the director of the Environmental Research Institute of the Academy of Sciences. Before that unprecedented series of nuclear explosions, he had arranged for Song Mingming to live in their ancestral home in Song Village and had given her the robot cat Zhuazhua as a companion. Song Village had a silver lake about six square kilometers in size. Along its shores, flowering trees bloomed like brocade, and the scenery was beautiful. Scattered sandbars in the lake attracted water birds and wild ducks to breed and rest every spring. In summer the lake would be stirred into lively chaos by playful children. Boys loved to jump naked into the water and splash about, causing the adults to call anxiously along the shore for those little monkeys to come home early. When the autumn wind rose, the silver lake became the domain of the village girls and women. They rowed small boats, laughing and singing as they gathered water chestnuts. The greedy ones would peel open freshly picked chestnuts and eat them raw—the fresh, tender fragrance tasted even better than when cooked. In the bleak winter the lake was at its quietest, yet when extreme cold arrived and thick ice formed, skaters and snowball fighters would turn the silver lake into a noisy playground once more. Through the changing seasons, the silver lake remained the unchanging source of joy for Song Village. The silver lake produced a special kind of small silver fish. Song Mingming often took Zhuazhua fishing. Sometimes they caught a whole bucketful. What they could not eat at once was made into silver-fish jerky. Zhuazhua loved helping Song Mingming clean the fish most of all. Its arms were a universal toolbox; whatever tool was needed could be drawn out to serve as a paw. Zhuazhua would use a sharp little blade to slit the fish open and remove the insides. Its movements were skilled and swift, and in no time a whole bucket of fish would be cleaned. Song Mingming would pickle the cleaned fish in salt water for several hours, then hang them up with string and hooks under the eaves. After three days the silver-fish jerky was ready. Every morning Zhuazhua cat watched Song Mingming eat the jerky with a steaming big bowl of plain porridge and thought it smelled wonderful! Its eyes would go straight with longing. If it could drool, the floor would certainly have been covered. To comfort Zhuazhua cat, Song Mingming shaped its energy blocks to look exactly like silver-fish jerky. This made Zhuazhua very happy, and it always praised them as the most delicious silver-fish jerky in the world! That day, after eating its silver-fish-jerky energy blocks, Zhuazhua cat put on its radiation-proof work suit, passed through the three corridors, opened the sealed hatch of the bunker, and stepped out into the scarred surface world left by the great nuclear explosions. The great nuclear blasts half a year earlier had not only destroyed most of the buildings on the surface where humans lived; nuclear radiation had also spread continuously across the Earth through air and water cycles. Countless humans and other living creatures had died. At the moment the great nuclear explosions began, Song Mingming received a phone call from her father telling her to take Zhuazhua and enter the bunker at once. Deep underground in the courtyard was a doomsday bunker strong enough to withstand the great nuclear blasts. It was stocked with all the necessities of life and could support them for at least three years. The survivors in the bunkers could still contact one another through computer networks. Although they could not travel freely, they could exchange news on social networks. Because the supplies in the bunkers would eventually run out, the survivors urgently needed to return to the surface, or at least obtain uncontaminated materials from above ground. Therefore, accurately mapping the pollution on the surface became the most urgent task, and such work could only be assigned to robots. The survivors had all kinds of robots around them—care robots, housekeeping robots, companion robots, pet robots, and more. All of them were given ground detection missions, and Zhuazhua was assigned one too. The first time Zhuazhua returned to the surface, it was so shocked it almost short-circuited. The once-lively Song Village, where willows had shaded the paths and chickens and dogs had called to one another, had become a dead, silent wasteland. The silver lake no longer held its former beauty. Its deep-black surface was covered with dead fish and algae. When the wind passed, the stagnant water barely rippled, and a heavy stench drifted about. No living people, no living animals!—that was Zhuazhua cat’s work report on the first day. When Song Mingming watched the memory playback of that day, she broke down and wept. Even worse, she had also lost contact with her father. Faced with such a terrifying doomsday scene, a fourteen-year-old girl could only hold her robot cat and cry together. In the days that followed, Zhuazhua went to the surface every day to carry out detection missions. Because the detection had to be done inch by inch, collecting pollution data from every bit of soil and plant, in one month’s time the area Zhuazhua had surveyed was only one percent of Song Village. On this particular day, when Zhuazhua was detecting in a small grove of trees, it suddenly felt a thick smell of blood coming from behind. Before it could react, a furry mass came whistling through the air and knocked it to the ground, then began frantically biting its arm. Zhuazhua looked carefully and saw it was a big dog with long strings of drool hanging from its mouth and bloodstained fangs bared. The dog’s face was already swollen and deformed, and its two eyes were full of blackened blood vessels, looking like a pair of rusty bronze bells. Zhuazhua had never fought before and had no combat programs installed. For a moment it did not know what to do and could only shout loudly, “We want peace, not fighting!” But the big dog paid no attention to Zhuazhua’s cries and bit more and more frantically. Suddenly there came a loud “bang,” and the dog fell to the ground. Zhuazhua seized the chance to break free and struggled to its feet. It saw that the dog’s face had been blown into a bloody mess; it was breathing its last. It turned out the dog had bitten one of Zhuazhua’s high-energy battery blocks and caused an explosion. Still shaken, Zhuazhua cat quickly repaired its damaged radiation suit, patted its chest, and said with relief, “Luckily I carry the most delicious silver-fish jerky in the world!” There was a collar around the dog’s neck. Zhuazhua recognized it as a dog from a family in the village, named Big Buddy. It had originally been a proud German Shepherd, usually not very friendly to strangers, but well-trained and never given to attacking. At this moment Zhuazhua cat noticed that the radiation detector in its paw was clicking nonstop. Big Buddy had already been mutated by radiation. Its aggressiveness might have been caused by the mutation, or by extreme hunger… or perhaps Big Buddy was not the only mutated living creature still surviving in Song Village… By then the sky had grown dark. A cold wind scraped through the trees, making a howling sound like ghosts crying and wolves wailing. Terrified, Zhuazhua cat meowed loudly and ran with all its might toward the bunker. When it reached the bunker entrance, Zhuazhua cat took off its heavy radiation suit, used the last of its strength to open the sealed hatch, and then, just as at the beginning of this story, tumbled and crawled back into the bunker.

Song Mingming recognized that the one who had attacked Zhuazhua was Big Buddy, and she breathed a sigh of relief—thankfully it wasn’t some particularly strange demon or monster. She switched off Zhuazhua’s memory recording and began repairing its damaged body. By now Zhuazhua had fully charged and had returned to its usual talkative self. Song Mingming used a small welding torch to mend Zhuazhua’s arm, while the cat chattered nonstop, repeating over and over how terrifying Big Buddy’s attack had been, how imposing the old Big Buddy used to look, and how regrettable it was that Big Buddy had died this way. Every time the welding torch sizzled, Zhuazhua would jump and cry out in exaggerated alarm. Needing to concentrate on soldering the circuits, Song Mingming finally snapped, “Zhuazhua! If you don’t shut up, I’m going to turn your voice off!” At times like this Zhuazhua had no choice but to mute itself; otherwise it simply could not stop talking. Song Mingming worked intently for the better part of an hour and finally finished repairing Zhuazhua’s arm. She let out a long breath and said to the cat, “All right, you can get up now, you little chatterbox.” Zhuazhua sprang up from the floor, shook its arms, flexed its claws—good as new. But then… Zhuazhua looked itself over, noting the various shallow dents large and small covering its body, and its expression grew a little unhappy. Song Mingming, still packing away her tools without looking up, said, “Zhuazhua, fixing the outer shell isn’t easy. When I have free time I’ll make you a brand-new set, but it will take quite a while to finish!” Zhuazhua asked with a worried frown, “How long will it take?” Song Mingming thought for a moment and replied, “Because I have more important work to do, and helping you look pretty is relatively secondary—of course, looking pretty is very important to you—so I’ll try my best to finish it by your birthday, okay?” “My birthday is July 30th at 15:10. From now until then there are still 81 days, 20 hours and 37 minutes.” Zhuazhua blinked its eyes and calculated it instantly, then cheered, “Wonderful! This year’s birthday is really worth looking forward to!” Song Mingming smiled and tapped Zhuazhua on the head. “Honestly, how can a little robot cat have so many vanity problems?” Zhuazhua tilted its head up and answered with proud coyness, “Daddy said that only things that aren’t perfect are cute!” Song Mingming laughed. “All right, I admit it—you really are very cute. You’re the best gift Daddy ever gave me! No contest! —Now I’m hungry. You go cook, and while you’re at it test whether all your functions are working normally, okay?” Because the curious Zhuazhua Cat always drooled with envy whenever it watched Song Mingming eat, she had programmed it with all sorts of recipes covering the essence of food cultures from around the world, turning Zhuazhua into a master chef. No matter what ingredients it was given, Zhuazhua could instantly create delicious dishes that looked, smelled, and tasted wonderful. The moment it heard it was time to cook, Zhuazhua became extremely happy and quickly agreed. “Mm-hmm! What would you like to eat today? Yesterday you had stir-fried bean sprouts, the day before that pumpkin cakes, the day before that oyster-sauce lettuce, the day before that candied sweet potatoes, the day before that garlic smashed cucumbers…” “Then let’s have a meat dish today!” Song Mingming interrupted the chattering cat. “How about scrambled eggs with Chinese chives?” “Great! In that case, why not make dumplings filled with scrambled eggs and Chinese chives!” Zhuazhua rubbed its paws together eagerly. “Oh my, that sounds wonderful!” Song Mingming patted Zhuazhua on the shoulder. “Then I’ll trouble you, my master chef!” “Heh-heh!” Receiving praise made Zhuazhua extremely proud, so it held its head high and swaggered off to the kitchen with great ceremony. Readers may wonder why Song Mingming and Zhuazhua Cat, living in an isolated bunker, could still enjoy such a rich variety of food. That requires starting with the design of this bunker. The growth of Earth’s living things requires three essential elements: water, sunlight, and air. First, water. If the water of Song Family Village had been contaminated, then natural water from outside must never be allowed into the bunker. Therefore the bunker’s water could only come from clean water stored in advance and from synthetic water produced inside the bunker. Synthetic water is made by letting hydrogen and oxygen react under certain conditions to form H₂O—that is, water. Whether clean water or synthetic water, both were extremely precious and had to be recycled. It may sound a little disgusting, but a small portion of Song Mingming’s urine was used for drip-irrigation of the various vegetables grown in the bunker, while the majority was recycled into drinking water. Thanks to advanced equipment, the drinking water converted from urine was quite clean, and the recycling rate reached as high as 98 percent. Therefore, as long as they were careful and thrifty, the bunker’s water supply was not a problem. Next, sunlight. The bunker’s ceiling had three layers. The outermost layer closest to the ground above was a completely radiation-proof concrete slab. The second layer was special glass with partial radiation-proof capability. The third layer was ordinary glass with no radiation protection. Radiation particles around the bunker arrived and dispersed with the wind. Based on data from the outdoor radiation-detection devices, the bunker’s control system would automatically select the appropriate ceiling. For example, if external radiation was very strong, the first-layer concrete slab would seal tightly over the top of the bunker. If there was radiation outside but it was not strong and could be blocked by the second layer of thick radiation-proof glass, the control system would use only the second-layer ceiling, allowing a moderate amount of light to enter, which was beneficial for the growth of living things inside. If there was no radiation outside, the control system would use only the third layer of ordinary glass as the ceiling, letting sunlight pour fully into the bunker. —If the concrete ceiling had to be used for several days in a row, Song Mingming would turn on the indoor sun lamps to simulate sunlight. Thus the bunker never lacked the survival element of sunlight. Then there was air. The reason vegetables were grown inside the bunker was not only because eating fresh vegetables could supply the nutrients the human body needs, but more importantly because vegetables could perform photosynthesis and thereby guarantee the oxygen supply inside the bunker. Of course, whenever the outside air was free of radiation concerns, Song Mingming would open the bunker’s ventilation system and let safe air in. In summary, the three essential elements for survival in the bunker were all present. However, two more things were indispensable for sustaining life: food and energy. The bunker’s food sources fell into two categories. One was a large quantity of pre-stored food originally intended for space stations. These specially made foods had high nutritional value per unit and were very durable in storage, enough to guarantee Song Mingming three years of survival needs. The other was the vegetables Song Mingming grew and the eggs she raised inside the bunker. There was a vegetable plot and a chicken coop in the bunker. Various vegetables grew in the plot; the coop held one rooster and two hens, which produced an average of one egg per day. Precisely because of this, Zhuazhua —the robot cat implanted with a master-chef program—could prepare different dishes in endless variety and never be left with “clever paws but no rice to cook.” Even so, Zhuazhua could only pick a tiny amount of vegetables from the plot each day to improve their meals—after all, in the bunker the more important role of vegetables was to produce oxygen. Some readers may ask: when there is no sun, don’t the vegetables also release large amounts of carbon dioxide that the human body doesn’t need? No problem—carbon dioxide can be made to react with alkali to lower its concentration while generating precious water: CO₂ + Ca(OH)₂ ═ CaCO₃↓ + H₂O. Readers who enjoy chemistry can join Song Mingming in the laboratory and play with the generation and transformation of various substances; we will not elaborate further here. Now for the energy inside the bunker. First, solar energy from outside could be used. Solar energy could be converted and stored in batteries; Zhuazhua’s silver dried-fish high-energy batteries came from solar power. Solar energy could also be used to electrolyze water, thereby storing the hydrogen needed for material transformations inside the bunker. When no solar energy was available, Song Mingming would use hydrogen and oxygen to make hydrogen-oxygen fuel cells. The electricity produced could keep all the equipment inside the bunker running. At the same time, as mentioned earlier, the chemical reaction of hydrogen and oxygen could also synthesize water (once again it must be stressed that water was the most precious resource of all. To save water, Song Mingming—this clean-loving little girl—drank urine-converted drinking water every day and could not bear to use water for bathing!). In short, the bunker was a complete survival system. As long as supplies were conserved and the daily operation of the equipment was carefully maintained, readers need not worry about Song Mingming and Zhuazhua’s survival for the next three years. And all the Great Nuclear Explosion survivors who were active on social networks were living in similar bunkers. —Before the Great Nuclear Explosion occurred, a company called Xinyuan Construction had built large numbers of doomsday bunkers all over the world. They became widely known for their fast construction speed, low cost, and reliable quality… Meanwhile, Zhuazhua quickly prepared a plate of fragrant dumplings filled with Chinese chives and egg. Song Mingming did not even dip them in vinegar; she popped them into her mouth one after another and ate with great gusto, muttering as she chewed, “So delicious! Zhuazhua, you’re the best master chef I’ve ever seen!” Zhuazhua sat at the edge of the table, propping its chin in its paws, staring unblinkingly at Song Mingming, just waiting for her praise. The moment it heard those words it was so happy it nearly fainted with joy. Just as Song Mingming and Zhuazhua were happily enjoying their dinner together, sudden bang-bang-bang knocking sounds came from above the bunker…