The hidden mission in the Key of Time game is the starting point of the Fallen Poetry, a coveted location in the Fallen Poetry. To complete this mission, you need to go to the riverside in the Twilight Forest, then enter a mysterious room and then enter a cave to find the ring. That's it.
1. First, go to the riverside in the Twilight Forest to look for clues. You may be able to get a hint and key items.
2. After finding the key clues, enter a mysterious room and solve a series of puzzles to obtain the next clue.
3. You need to go to the cave to find the mysterious ring. The cave is next to the river beach and you need to use goblin bombs to enter.
4. Use a fishing net to fish the goblin bomb in a place where fish swim in Huguang Town.
5. After successfully getting the ring, you will pass this hidden mission.