The sound of water suddenly tightened, as if someone had overturned a whole row of tin barrels in the distance.

The front of the raft plunged into a slanting wave, lifting Chen Hao half a foot off the ground. Just as his buttocks landed back on the plank, the back of his head slammed into the base of the pole. Before he could even finish his cry of "Ouch!", a second wave of impact slammed in from the side, making the entire raft shake three times as if it had been lifted up.

"Move to the left! Press down on the front beam!" Nana's voice was as steady as flowing water.

Chen Hao scrambled to the left, ignoring the pain as his knees hit the crossbeam. Just as he landed, he heard a sharp "snap"—a rope on his right side snapped, and a side plank popped up, whipping through the air like a dead fish's tail.

"Didn't you say it could bear 500 kilograms?" he roared.

“That’s a rope.” Nana knelt on one knee at the stern of the raft, her arm slightly outstretched. “You’re 620 now.”

"I didn't ask you to weigh yourself!"

Before the words were finished, the passage ahead suddenly narrowed, the cave wall shrinking into a slit between the water and the rock. Right in the center of that slit, a large, dark rock stood there, its top protruding more than half a meter above the water, its edges worn smooth and shiny, clearly a checkpoint carved out by water over the years.

Their raft was hurtling toward the sharp corner of the rock at an unreasonable speed.

“Deflection failed.” Nana stared ahead. “Insufficient magnetic thrust.”

"Why didn't you say so earlier?"

"I said the water flow is 2.8 meters per second."

"But I have no idea! I'm not a speed camera!"

He cursed as he reached for the pole. The pole was tied too tightly; he tugged at it twice without loosening it, so he lunged forward, biting the knot in his teeth and pulling hard. The rope finally snapped, and his hand slipped, nearly causing the pole to fall into the water. He managed to hook the end with his toes and pull it back.

The stone was getting closer and closer, less than ten meters away by sight.

Five meters.

Three meters.

He forcefully thrust the pole vertically into the gap between the rock and the raft, the pole head wedged into a recess in the rock face, and the pole tail braced against the main beam of the raft. He gripped the middle section tightly with both hands, leaning back as if he were wrestling with a runaway vending machine.

"Power up!" he shouted.

Nana immediately understood the intention. She quickly moved to the other side of the support pole, the robotic arm engaged the joint of the wooden beam, and at the same time activated the miniature thrusters on her legs to apply pressure in the opposite direction.

The raft emitted a teeth-grinding creaking sound, as if someone were gnawing on rusty steel bars.

The front end is tilted outwards a little bit.

One inch.

Half a foot.

Just as the raft was about to glide past the sharp rocks, a sudden undercurrent surged up from below, as if the entire body of water had been kicked from underneath. The raft lurched violently, and the poles slipped instantly, producing a screeching sound.

"Oh no!" Chen Hao's wrist went limp, and he almost dropped the object.

Nana reacted with lightning speed, her left hand lashing out to grab his wrist with such force that his bones cracked. Her right hand slapped directly at a joint on the bottom of the raft—the cross-shaped binding she had previously reinforced. A metal clip popped from her palm, precisely inserting into the knot to form a temporary lock.

Using this reaction force, she pushed herself forward, managing to widen the angle of deflection by another ten centimeters.

The raft finally slid past the rock face.

With a "crack," a piece of the tail section was scraped off, swirling as it fell into the rapids and was swallowed up in the blink of an eye.

The two remained frozen in place, maintaining their exertion postures and not daring to move.

Until a loud "boom" came from behind them, it was the collapse of a small section of the ceiling of the narrow passage they had just passed through due to the impact of the rushing water.

Chen Hao then slowly exhaled, and the pole fell onto the raft with a "thud".

"Next time... could you give us an advance warning?" he asked, panting. "Even just three seconds in advance would be helpful."

“Delay parameters have been recorded.” Nana withdrew her arm, her eyes flashing blue light. “We will optimize the prediction model later.”

Why do all your robots speak in such a hurtful way?

"I didn't poke it."

"Why didn't you say that when you grabbed my wrist earlier?"

"That's to prevent it from slipping out of your hand."

"Oh, so my life is just a 'get rid of risk'?"

Nana didn't answer, but instead looked down and scanned the raft structure: "The third and fifth connection points on the right side are slightly deformed, and it is recommended to repair them as soon as possible; the stability of the remaining side panels has decreased by 18%; the food pack is undamaged, the lighting tools are normal, and the communication module signal is stable."

"You actually remember priorities."

"I said that."

Chen Hao rubbed his numb arms and slowly climbed to the center of the raft. He unpacked his backpack, took out a small cloth bag from a hidden compartment, and poured out a few screws and two nuts.

"Strategic reserves activated." He said, and then began to tighten the loose connection.

Nana crouched down to help him secure the position: "Use the standard torque of M4 to avoid over-tightening and causing the wood to crack."

How do you even know this?

"The database contains 2,376 basic maintenance manuals."

"Then why don't you go and build a bridge? You've been reduced to drifting on the underground river with me."

"I don't decide how tasks are assigned."

“That’s true.” He tightened the last nut, clapped his hands, and said, “If it weren’t for you, we’d be pancakes on the rocks by now.”

"The physical form will not change into food."

"I did not mean that."

"I know."

The two were quiet for a while. The water was still rushing, but it no longer seemed to be crashing around haphazardly as before. The roaring sound in their ears gradually subsided, as if the washing machine had switched from the spin cycle to the rinse cycle.

Chen Hao leaned against the main beam, feeling his legs begin to ache. That last push had taken too much effort; even his fingers were trembling slightly.

"How many more of these hell gates are ahead of you?" he asked.

"Based on the current flow rate and terrain slope, there are still continuous cascades ahead, expected to last for 470 meters."

"Can't you just speak like a human being?"

"That means the next 470 meters are all steep slopes and sharp bends."

"I knew it."

He struggled to sit up straight and casually re-tied the pole back into place. This time, he wrapped it around twice more and even tied a double knot.

Nana then activated the environmental monitoring program, constantly adjusting her stance to adapt to changes in the water flow. Her feet remained firmly planted on the raft, and occasionally a faint electrical hum could be heard from her joints.

“You know what,” Chen Hao suddenly grinned, “being with you, even though I always get teased, makes me feel at ease.”

Nana glanced at him, and the blue light flickered slightly.

"I am just executing the program."

“Alright, program.” He waved his hand. “Now execute a new instruction—don’t just stare at the data, look up and see where you’re going too.”

"The area is now under surveillance."

“That’s not what I meant.” He pointed to the gradually widening river ahead. “I meant that you should learn to be nervous too. If one day you suddenly say, ‘I’m a little scared,’ I’ll actually feel like you’ve come alive.”

"Fear is not on the feature list."

"What a pity," he sighed. "You happen to lack the most useless yet most useful emotion in humanity."

Nana was silent for a moment, then suddenly said, "Just now, my system response was delayed by 0.3 seconds."

"Um?"

"Normally, the decision output should be completed within 0.1 seconds. Delay means that the processing load is overloaded, or it may be that there are redundant branches in the decision path."

"so what?"

"I don't know whether to save the raft first or pull you out first."

Chen Hao was taken aback for a moment, then burst out laughing: "Aren't you panicking?"

"I am merely stating an anomaly."

“But you’ve never been ‘abnormal’ before.”

Nana didn't say anything more. She simply raised her hand slightly to check if the emergency light strap tied to her arm was secure.

The current propelled the raft forward. The cave ahead grew higher and wider, and faintly visible above were patches of glowing moss, like stars in the night sky.

Chen Hao leaned against the wood, his breathing gradually becoming steady. He checked his pockets to make sure the cookies were still there, then looked at Nana's position and noticed she was standing a little further forward than usual.

“Hello,” he said.

"What?"

"If we hit a rock again next time, we'll support each other."

"Efficiency is not as good as clear division of labor."

"But I don't want to shoulder this alone."

Nana turned to look at him; the blue light flickered quietly in the darkness.

“Okay,” she said, “but you have to promise not to let go.”

"make a deal."

The words had barely left his mouth when the raft suddenly sank, as if it had jumped from a high platform into a deep pit. A clear drop appeared in the water ahead, and a small waterfall came into view.

Chen Hao grabbed the rope loop, and before he could even utter a half-uttered "Holy crap!", he was flung forward.