Merlin's A Bit of Help From Your Friends quest in Disney Dreamlight Valley is far from short. You'll need to complete three quests for Gaston, EVE, and Rapunzel before you can reenter the ruins and open the trapdoor, but it's all worth it as completing this questline will eventually lead you to Oswald.
A Little Help from Your Friends Quest Guide in Disney Dreamlight Valley
Oswald is the latest character added to the Disney Dreamlight Valley A Rift in Time expansion. You will need to own this expansion to enjoy the A Bit of Help From Your Friends quest and discover this monochrome character.
Once you have the new expansion, here's how to complete the mission.
In Disney Dreamlight Valley, you can complete the Merlin's A Bit of Help From Your Friends mission by completing the following objectives: