Two sisters, Trang Trang and Bong Bong, came to visit. That afternoon, Bi Bi and the two sisters went up to the third-floor bedroom to take a nap. Their grandfather had instructed them to take a nap because it was good for their health.

Before going downstairs to rest, their grandfather assigned tasks:

• Trang Trang, you will be in charge of the group. No mischief or noise. Everyone should lie quietly and sleep.

After their grandfather went downstairs for a while, Trang Trang started snoring... snore... snore... Seeing that Trang Trang was already asleep, Bong Bong raised her head, thinking of doing something mischievous. But when she heard their grandfather's footsteps coming up, Bong Bong immediately closed her eyes and pretended to be asleep. Bi Bi did the same.

Their grandfather entered the room, slightly suspicious because he had heard a noise, but now everything was silent, as quiet as boiled meat. He leaned down, took hold of Bong Bong's hand, and let it go. The hand fell with a thud. Then he lifted Bong Bong's leg and let it go. The leg also fell freely and made a thumping sound. Satisfied that the children were sleeping, their grandfather went downstairs.

A while later, Bong Bong convinced Bi Bi to play with water in the bathroom. They found a roll of toilet paper, and Bong Bong started pulling it continuously. Bi Bi intended to ask her sister to stop because their grandfather had forbidden mischief, but seeing how happy Bong Bong was, Bi Bi stopped protesting. Bong Bong enjoyed watching the roll spin, so she kept pulling. The entire roll of toilet paper unraveled into a pile of white sheets on the floor. Bong Bong tore the sheets into pieces and threw them all into the toilet bowl. Bong Bong flushed the toilet. Swish... swish... swish... The water swirled in circles, but only a small amount went down, while the rest filled up the toilet bowl.

Bong Bong was frightened, her face turned pale, and then she saw Bi Bi playing with soap, smearing it all over herself. Bi Bi even scrubbed their grandfather's bathtub. Bong Bong found it amusing and forgot about the clogged toilet. She took a basin and sprayed soap with Bi Bi, washing and scrubbing. The bathroom was filled with bubbles, shining with rainbow colors, making the two sisters even happier. The bathroom became filled with soapy messiness, slippery and slimy.

Seeing the clogged toilet, Bi Bi poked it with a stick. Hearing the noise, their grandfather came up and asked, "Aren't you children sleeping? What are you doing?" Bi Bi replied, "We're unclogging the toilet for you, grandpa." Their grandfather glanced into the bathroom and chuckled, "You two are so helpful. First, you clog it, and then you unclog it. Well, go inside, and go to sleep."

After the children left, their grandfather entered the bathroom and slipped, almost falling down. Luckily, he held onto the door to prevent himself from falling.

Returning to the room, their grandfather asked, "Only Trang Trang is sleeping? Why aren't the rest of you sleeping?" Bong Bong replied, "We cleaned the bathroom for you, grandpa." At that moment, Bi Bi heard a whisper from a fairy, "That's a lie, Bi Bi. You shouldn't say that." Without waiting for their grandfather to ask further, Bi Bi said, "Grandpa, we were mischievous. I played with soap, and Bong Bong played with toilet paper!"

Their grandfather laughed warmly and patted Bi Bi's head. "You're right," he said. "So what should we do now?"

"Now, we'll clean up and then take a nap," Bi Bi replied.

Their grandfather led the two sisters to the bathroom, which was covered in soap, with their hair, hands, and clothes all slippery. He instructed them to change their clothes, dried their hair, and gently lay down next to Trang Trang. Bong Bong whispered to Bi Bi, "Trang Trang didn't do anything as the group leader; she just slept!" Bi Bi followed their grandfather's example, placing two fingers on her lips and making a soft sound, indicating they should stay quiet so that Trang Trang could continue sleeping. And soon, sleep embraced the two sisters without them even realizing it...