Though Cider Lake was smaller than Dragonspine, exploring it posed an even greater challenge.
Visibility underwater was many times worse than in air—even a pristine lake like Cider Lake was no exception. And the deeper you went, the worse it got—not because of sediment, but due to lack of light.
Exploring underwater was like walking through dense fog. The deeper the water, the thicker the fog, and the longer it took to explore.
And Vision bearers still needed to breathe—otherwise, they'd drown. In Dragonspine, one could bring a heat source. Underwater? What, an oxygen tank?
Even though they could stay submerged longer than ordinary people, they'd still have to resurface repeatedly. Dive, rise, dive again. Time-consuming, to say the least.
These two factors combined made it a serious time sink.
Victor Wang wondered how many Vision holders the organization had in Mondstadt. If only a handful of people were expected to map out the entire lakebed, it would indeed be a long, grueling mission.
But… isn't this perfect timing?
I'm blessed by the Sprite of the Springs!
Feigning casual interest, Victor asked, "So what happens if you do find something down there?"
"Whether it's a leyline node or a god's corpse, the organization can handle it. This operation just needs to pinpoint any anomalies."
"Will there be any kind of reward if it succeeds?"
Diluc didn't answer directly—instead, he asked, "You do know the organization's core mission, don't you?"
"For a better tomorrow." Of course, Victor knew. It was practically impossible to forget.
"This operation was initiated by a member who was harassed by the Slimes. It's for their better tomorrow—and helps eliminate a safety risk for Mondstadt at the same time."
"That's a reasonable cause. And the organization acts on reasonable causes."
"If you really want to talk rewards—well, in the organization, the 'weak' provide intelligence for the 'strong', and the 'strong' offer protection in return. Participating in actions like this makes it easier to enjoy free intelligence with a clear conscience."
Diluc continued to polish the same row of glasses under the bar, wiping them over and over.
"Sounds good."
Diluc's hand paused for a beat. Victor's mention of reward had an edge to it—one that felt like a warning. It wasn't uncommon for young people to only act when there was gain to be had... as long as they didn't forget duty.
But perhaps he had misunderstood Victor.
"I didn't mean that as a lecture. I joined the organization for personal reasons too."
"You're not obligated to take part in any operations. Your goals align completely with ours—so any effort you make is already helping the 'weak.'"
"No, no—this operation, I have to join. I can stay submerged for extended periods. I might be the most suitable person in Mondstadt for this. As for where that ability comes from... please allow me to keep that private."
"Oh? That's... quite the unexpected asset." Diluc finally stopped polishing. "When are you planning to leave Mondstadt?"
"Let me think... Three days left. That should be enough, right? Or should I go now?"
"No need. It's too dark underwater at night. Efficiency drops. Daytime's better—but you'll still need a light source."
Diluc pressed his fist against the tip of his nose, thinking aloud. "The lighting tool is ready. I didn't bring it with me, though. Come back tomorrow morning. Once you have it, you can start."
"Alright."
Once Victor had left, Diluc finished cleaning the glasses, turned off all the lights, locked every door of Angel's Share, and made his way through the darkness toward the Ragnvindr estate.
The Ragnvindr family—alongside the Gunnhildr and Lawrence families—was one of the three most prestigious lineages in Mondstadt's modern history.
But unlike the other two, the Ragnvindrs had always had a sparse lineage. Diluc's father and grandfather were both only sons.
Diluc technically had a younger brother, though not by blood.
Even so, with a Vision gained at age ten, appointed the youngest cavalry captain in the Knights' history at fourteen, controller of half the Mondstadt wine industry, and chair of the Mondstadt Merchant Guild, Diluc alone was enough to rival the other two families combined.
In many ways, he was the uncrowned king of Mondstadt.
Still, the Ragnvindrs did have distant relatives.
The so-called "cadet branches" were descendants of past family heads' siblings, making them distant cousins of the current head. Unlike the sprawling branches of the other noble houses, Ragnvindr's cadets were few—and mostly involved in the wine business. Unlike Diluc, who lived at Dawn Winery, they stayed in the city estate.
Of course, Diluc had a room there as well. On days he didn't feel like returning to Dawn Winery, he'd sleep here.
"Charles."
"Master Diluc, you're back."
"Bring out the tools we prepared earlier. Have the 'Gearwright' take a look."
...
Early the next morning, after his daily training, Victor knocked on the door across from his own on his way out.
It was Lumine's last day in Mondstadt. She would be heading to Liyue tomorrow.
No one answered.
"Always up so early. Don't sleep enough, your skin's going to suffer."
["Hmph! I bet that clueless little glutton of an unknown flying object dragged Teacher Lumine off for breakfast the second she opened her eyes!"]
"Teacher Lumine?"
["Yeah! She's Master's teacher, so that makes her my teacher too!"]
"You really know how to ride those coattails, don't you?"
["Hmph! What's wrong with that?"]
What was the term again? The title calculator had no entry for "master's teacher."
Victor shook his head and bought a grilled flatbread to nibble on as he made his way to Angel's Share.
It was still early—no one drinking yet. But Diluc was already seated quietly at the bar, with Charles behind the counter.
Sensing movement behind him, Diluc turned his head.
"You're here?"
"I'm here."
Diluc took out a palm-sized glass orb. Inside it floated a smaller orb, which in turn held another, and so on—nine nested layers, with a solid core at the center.
"This is called a Day Pearl. Very easy to use—just inject some elemental energy and it will light up." He released it, letting the pearl fall gently into Victor's hand.
"Normally, each explorer gets one. Yours has been specially modified. Different amounts of elemental energy will trigger different light levels. It should be enough to illuminate a wide area underwater."
Victor infused a bit of energy. Since Diluc hadn't minded Charles being there, he didn't either.
At the first charge, the innermost layer glowed white—faint under the tavern's warm amber lighting.
With a little more power, the second-to-last layer lit up too, bright enough to make Charles squint.
"Ah—sorry!"
"It's fine," Charles replied with a slight shake of his head.
"Alright, I'm heading out then."
"Stay safe," Diluc said simply.
...
Cider Lake's shallows glistened under the autumn sun, clear enough to see the bottom.
Unless polluted—like the Mikage Furnace region in Inazuma—most natural waters in Teyvat were crystal-clear. Whether this was intentional world design or a nod to unpolluted ecosystems was unclear.
Victor exited through the side gate and stepped into the lake at a quiet spot. Though it was late autumn, the water only felt mildly cool through his clothes.
He remembered Paimon saying Cider Lake never froze.
Not just Cider Lake—aside from Snezhnaya, most regions rarely see frozen waters.
Now he knew that Teyvat's calendar marked it as autumn, with winter just around the corner. Liyue's Rite of Descension happened at the start of winter; the Lantern Rite came at year's end.
Overall, Teyvat had a climate well-suited to humans. Seasons weren't sharply divided, so if you wanted bitter cold or blistering heat, you had to visit places like Dragonspine or the Great Red King's Desert.
"But Cider Lake water really is sweet. And the bass here really does taste better than anywhere else."
["Mmm! I wanna eat some too!"]
"When you grow a mouth, I'll treat you."
"..."
Victor casually dismissed Little Wen's daydreaming and walked toward deeper water. Even with the Spring Spirit's blessing, his clothes still got wet.
"Ugh. Uncomfortable."
The water reached past his belt, over his chest, past his mask. His nose filled with lakewater. But after forcing his body to stay still and getting used to the sensation, it was no different from moving through air.
He walked directly on the lakebed. A thin layer of silt coated solid stone. After fifteen minutes of trudging, he finally reached a vast, dark trench.
Movement was sluggish underwater—but if he could train himself to move on par with land, it would greatly enhance his martial technique and agility.
The thought crossed his mind—then vanished as he stepped into the watery abyss.
Down he went.
Deeper.
And deeper down below.