The current suddenly slid down, the front of the raft plunged into the water and bounced back up, and Chen Hao was thrown against the crossbeam, almost bumping his nose.

"Ouch, my back!" He grimaced and pulled back, still gripping the rope ring tightly. "Is this river temperamental or has it taken the wrong medicine?"

Nana didn't speak, her blue light flashing a few times in her eyes, as if she were flipping through an instruction manual. She pressed down on a raised wooden board with one knee, and with a slight movement of her arm, tightened the section of rope that had been loosened earlier.

“That sudden acceleration was caused by a change in slope,” she said. “It will likely happen more frequently in the future.”

"Why didn't you say so earlier?" Chen Hao said breathlessly. "I thought we were taking a leisurely sightseeing boat ride."

"You didn't ask."

"How was I supposed to ask that! I'm not a water conservancy expert, I can't even swim properly without a doggy paddle!"

He cursed as he rummaged through his backpack, his movements much more efficient than before. That sway earlier had made him realize one thing—if he didn't secure his things properly, the next time it might not be as simple as just tripping and falling.

He pulled out a roll of thick rope and swung it open with a whoosh: "We can't rely on luck anymore, we have to tie everything we can tightly."

Nana glanced at it: "I suggest prioritizing securing high-value, easily lost items. Food, lighting tools, and communication modules should be the top priority."

"You even have priorities?" Chen Hao snorted. "If we lose our food later, let's see if you prioritize eating."

As he spoke, he began to pull out the bag containing compressed biscuits, wrapped it around the main beam three times, tied a tight knot, and then wrapped it around the beam again to secure it. Not satisfied with that, he tied it in a double knot.

"This is our last ration." He patted the bag. "If you short-circuit, you can still charge it, but if I faint from hunger, there's no one to carry me."

“I can drag you to a safe area,” Nana said, “but the process may affect your comfort.”

"Come on, last time you said 'weight allowed,' and then you actually carried me like I was a sack of potatoes. I was so embarrassed."

"Efficiency first."

"Don't you robots have any humanity at all?"

"I don't have an emotion module."

"Then stop interfering with me all the time."

"Survival security does not fall under the category of emotions."

Chen Hao rolled his eyes and continued working. One by one, the kettle, emergency blanket, and flashlight were strapped to the frame, and he patted each item lightly after securing it, as if greeting his old buddies.

Nana has already started the scanning process, checking the device status item by item.

"Two lights, with batteries at 87% and 79% respectively; the communication module has a normal signal strength, but its transmission distance is limited due to interference from the rock strata; the location of the spare buoy is clear, in the outer compartment of the backpack."

“I can’t remember all that data,” Chen Hao interrupted her. “Just tell me—how many were broken?”

"zero."

"That's good then." He breathed a sigh of relief. "As long as it's not broken, I'll treat it as usable."

He also secured the pole, a straight strip he'd picked from a dead tree, one end sharpened to prevent slipping, intended for use on the bank or for probing the way. After securing it, he even gave it a kick to make sure it wouldn't come loose.

"Now the problem is..." He sat down and rubbed his shoulders, "where should we stand to minimize the chance of flying off?"

“The center of gravity area.” Nana pointed to the area slightly forward of the center of the raft. “I suggest you stay here. I’ll be responsible for monitoring and balancing during the second half.”

"The division of labor is quite detailed."

"Maximize collaboration efficiency."

"Alright, then you're the captain, and I'm the coolie."

"I have no authority to appoint."

"Can't you just say something to my liking?"

“I’m telling the truth.”

"Can't you be a little more tactful when you tell the truth?"

Nana didn't respond to that, but instead reminded them: "The water flow ahead is continuously increasing in speed, currently reaching 1.2 meters per second. We expect to enter a continuous fluctuation zone in five minutes."

"What is a continuous fluctuation zone? It sounds like the spin cycle of a washing machine."

The analogy holds true.

"I knew it," Chen Hao grinned. "Our raft was bound to turn into a rolling drum sooner or later."

He stood up and stretched, his chubby arms drawing an arc in the dim light. Then, suddenly remembering something, he bent down and unzipped the bottom of his backpack.

"Oh, I almost forgot about this."

He took out a small cloth bag, which jingled.

"What is this?" Nana asked.

“Baby.” Chen Hao mysteriously opened a corner, revealing a few metal parts. “These are the screws and nuts left over from when I repaired you. I’ve kept them all this time.”

"use?"

“If any knot comes loose, we can reinforce it temporarily,” he said seriously. “That’s called a strategic reserve.”

“That makes sense,” Nana paused, “but you shouldn’t have kept the repair parts without permission.”

"Hey, I've handed it over now, haven't I?"

"It was handed over passively when it was about to be lost."

"Can you please stop nitpicking?"

"I'm just stating the facts."

"The truth is awful."

As the two were talking, the raft shook again, not a big one, but enough to make Chen Hao stumble and hit the side.

“I said…” He steadied himself by holding onto the piece of wood, “Shouldn’t we get a seatbelt? Or at least a rope to hold it in place.”

“There are no standard safety belts,” Nana said, “but you can make a simple restraint device using an emergency rope.”

"Then let's get one."

Nana immediately pulled out a piece of elastic fiber rope and quickly tied two loops on both sides of the raft, leaving an adjustable length in the middle.

"Sit down and test the tension."

Chen Hao obediently sat back down, put his arm through the rope loop, and tested the tension.

"It's still pretty solid."

"The maximum weight capacity is 500 kilograms."

Are you implying that I'm overweight?

"The data is free of subjective bias."

Why do all your robots speak with such a barbed tone?

I have no thorns.

Chen Hao was too lazy to argue anymore. He looked down and checked every binding point on his body. After confirming that they were all secure, he looked up at Nana.

"What about your side? Are you okay standing there?"

“The structure is stable,” she said. “My center of gravity control is more precise than that of humans, and I am more resistant to overturning.”

"What if you fall down?"

"I will automatically activate waterproof mode and attempt to return to the raft."

"But what if you get stuck in a crevice between rocks?"

"The probability is less than 0.3 percent."

"But what if?"

“There are no ‘what ifs’,” she said, looking at him. “There are only contingency plans.”

Chen Hao stared at her for two seconds, then suddenly smiled: "You know what? You may seem cold, but you're more reliable than anyone else when it really matters."

Nana's blue light flashed briefly, like a small fluctuation during a system restart.

"I'm just running the default program."

"Come on," Chen Hao waved his hand. "The program won't remember the time I gave you the last cookie."

Nana didn't respond to that, but simply adjusted her posture slightly, making sure her feet were firmly planted on the seam.

The current had noticeably quickened, and the roaring sound grew closer, like a giant blower operating in the distance. The stone pillars on both sides of the cave walls receded continuously, and in the interplay of light and shadow, some fine cracks could be seen spreading near the water's surface.

"Are you ready?" Nana asked.

"Almost there." Chen Hao gripped the pole tightly. "The food is tied up, the lights are on, and everyone's on duty... I think we've got everything covered?"

"The inventory list is 98% complete."

What about the remaining two percent?

"You can't carry oxygen, and you haven't emptied your bladder."

"Hey! You call this even a valid argument?"

"Physiological needs are part of the preparation for the expedition."

"You're really well-rounded."

"I just don't want you to request a stopover midway through the voyage."

"Thank you so much."

Chen Hao muttered to himself, then looked around one last time to make sure everything was in place. He reached out and touched every knot on the edge of the raft, tugged hard, and only felt relieved when he heard the wood make a dull "thud."

"Alright," he said. "Now we just have to see how far this broken river wants to go."

Nana's eyes continued to flash blue light as she performed final data calibration. Her arms were slightly outstretched, maintaining a ready posture that could be adjusted at any moment.

Chen Hao sat at the front, his hands resting on the pole, his breathing gradually becoming steady. The panic from before had been replaced by a strange focus, like a student still changing multiple-choice questions in the last minute of an exam, knowing that time was running out but still wanting to do every detail perfectly.

The current propelled them forward slowly; the passage ahead seemed to narrow, and the light grew dimmer. But these were not the most obvious signs.

What truly made my heart clench was the change in the sound of the water.

It was no longer a uniform flow, but a rhythmic impact, one after another, as if something was waiting for them below.

"They're here," Nana said softly.

Chen Hao nodded without saying anything.

He raised his right hand and made a downward pressing gesture, as if telling himself to calm down.

The raft continued to glide forward, getting closer and closer to the source of the sound.

His left hand was still gripping the rope loop, his right hand was tightly holding the pole, and his eyes were fixed on a tiny ripple on the water ahead.

The ripple was widening and accelerating at a speed visible to the naked eye.