With Great Power…

With Great Power
Merlin needs to tell you about something important.
Merlin and some other villagers fear the Forgetting is happening again. Dreamlight Valley’s fate lies in the Sea Witch’s hands.
You promise to free Ursula from her cave in exchange for information. If you want to stop what’s happening, you need to find the Orb of Power in a secret cavern locked by a key she gives you.
Finding out how to open the cave was the easy part. Inside, you discover a series of vexing riddles.
After overcoming the tests and restoring the Orb of Power, you have no choice but to tell Merlin about Ursula being free.
You get this quest after opening up Dazzle Beach. With completing this quest, you get Ursula in your Valley. Here you can find all your subjects for the quest and explanations behind it. 

• Talk to Merlin: you can find on the map where he is.
• Explore the cursed cave: go to Dazzle Beach. You can best take the entrance on the left side from Peaceful meadow. If you then follow the wall that lies next to the Forest of Valor, you will find a gave. Talk over there to Ursula.
• Place Ursula’s Crystal Key in a device near the locked entrance to a cave on Dazzle Beach: At the same side of the beach, you can find a locked entrance. This one is in the wall between Peaceful Meadow and Dazzle Beach. Interact with the pillar next to it and place the key in it.
• Explore the Mystical Cave: walk towards the first magical gate.
• Find a way to remove the first magic gate in the mystical gave: the first magic gave can be removed with 3 gems; an Aquamarine, Peridot and a Garnet. You can find an aquamarine with mining at Dazzle Beach or Forest of Valor. Peridot can be found with mining at Dazzle Beach or Peaceful Meadow. A Garnet can be found with mining in the Plaza or Peaceful Meadow.
• Find a way to remove the second Magic gate in the Mystical Gave: the second gave can be removed by planting three seeds; a carrot, wheat and a tomato. You can buy tomato seeds at Goofy’s Stall on Dazzle Beach for 8 Star Coins. It takes 25 minutes to grow, and you have to water it two times. You can get wheat seeds at Goofy’s Stall in the Peaceful Meadow for 1 star coins. It takes 1 minute to grow the wheat seeds. Carrot seeds you can get by removing night thorns in the Plaza or Peaceful Meadow. The Carrot seeds take 15 minutes to grow.
• Find a way to remove the third Magic Gate in the Mystical Gave: you have to cook a carrot, wheat and tomato. It will make together a veggie pasta. After you have eaten it, the gate will disappear.
• Fish the Orb of Power out of the water in the mystical gave: use your fishing rod to get the orb out of the water.
• Place the orb of power in the pillar near the Mystical Cave: go back outside and place the orb in the pillar.
• Return to Ursula in the cursed cave near Dazzle Beach: go back to the gave and talk with Ursula.
• Let Merlin know that Ursula is free: you can find on the map where he is. With talking to him, you will end this quest.