Li Li was taken aback. “Not the beads? Then what is it?!”

“It’s light.” Bai Youwei answered.

“Light?” Li Li couldn’t make sense of it. “Why would it be light? Heavy summer rain falls, pitch-black, and the treasure cannot be seen… why would the treasure be light?”

Bai Youwei explained: “The nursery rhyme doesn’t say the water monster can’t find the treasure — it says the water monster can’t see the treasure.”

“That still doesn’t mean it’s light,” Li Li disagreed, frowning. “And how do you explain the beads? Why would all those beads suddenly appear in the places that had been flooded?”

Bai Youwei was silent for a moment, then said, “Actually it’s not hard to understand. The bear brought fish — so by the same logic, fish can bring beads.”

Li Li froze.

Right…

The bear had brought fish — so why couldn’t fish bring beads?

Were the beads they found actually the reward for completing the second round?

“Reconsider the nursery rhyme.” Bai Youwei softly recited it aloud: “In spring, the bear woke up — it lost two children and was so distressed; in summer, heavy rain poured down — pitch-black, the treasure nowhere to be seen; in autumn, who came along? Look — the Nail-Tooth Monster opened wide, but where did all its teeth go…

Spring and autumn both name the guest — so why not summer? The nursery rhyme could easily have been written as: ‘The water monster cannot see its treasure anywhere.’ Why wasn’t it written that way? Why insist on saying ‘pitch-black, the treasure cannot be seen’?

Because ‘Pitch-Black’ is the water monster’s name. Without ‘light,’ it cannot see its treasure — it cannot see anything at all!

And we were all misled by the word ‘treasure’!”

“So what you’re saying is, the task we should be doing isn’t finding the treasure.” Yan Qingwen said. “It’s helping the monster see its treasure?”

Bai Youwei nodded and said, “Just now when I fell in, it was very dark underwater. Even when that fish swam past, it was still very dark — it was extremely sensitive to light sources. Also, it resembled an anglerfish. By rights, its dorsal spine should carry a bioluminescent lure…”

“That’s the glandular cells.” Li Li couldn’t help but add. “An anglerfish’s glandular cells secrete luciferin, which reacts with oxygen in a chemical reaction catalyzed by luciferase to produce light. But where would we get glandular cells for it? Are you suggesting we give it the flashlight?!”

“Not the flashlight.” Bai Youwei shook her head slightly. “If my inference is correct, there should be a light bulb somewhere in this house that corresponds to it.”

“A light bulb?!!” Li Li exclaimed in an enormously exaggerated voice! He thought Bai Youwei was completely off her head!

Yan Qingwen nodded: “This anglerfish monster can generate electricity. A light bulb is actually quite plausible.”

Li Li: “…”

“But this house has so many light bulbs — which one is it?” Teacher Cheng asked.

“The one that doesn’t light up.” Bai Youwei’s tone was certain.

Everyone exchanged glances.

With so many light bulbs, which one was the one that didn’t light up? Right now the first and second floors were both flooded and the power was out — even if they wanted to test them, there was no way to do it, unless…

Their eyes drifted, almost of their own accord, to the fluffy rabbit in Bai Youwei’s arms.

Shen Mo spoke up: “The bulb in the storage room doesn’t light up.”

Everyone was startled.

“I searched through the storage room,” Shen Mo said. “I flipped the switch a few times; the light didn’t come on. I assumed the bulb was burned out. Now that you mention it — that seems to be the only room in the entire house where the light doesn’t work.”

Yan Qingwen heard this and followed on: “Here’s what we do then — you go get the bulb from the storage room; I’ll remove a few other bulbs from rooms we haven’t tried yet. Then we come back and compare.”

Shen Mo gave a slight nod.

The two men had their plan worked out, and went down into the water one after the other.

Outside, the torrential rain kept falling.

Floodwater had swallowed everything. Out in the expanse of water, only a tiny triangular rooftop was visible. The people inside, perched on half a floor of the attic, waited for the final answer…

—