NIN and SO fall into a cave while they are searching for the herb. Unexpectedly, they find the herb in the cave and collect it for KAI YAU. When they deliver the herb to the house of KAI KAU, they realize the aging problem of KAI KAU is serious and his retirement is appropriate. Therefore, NIN and SO exchange their marvelous stone as souvenir and their relationship grows rapidly after this incident. NIN dates SO for a special lights event; meanwhile, maid TSUI also dates YUEN to the event.