Step 1: When you reach Lucid's realm, head into the house until you reach an area with bookshelves, crates, and other items. On the wall with Lucid's portrait, there are various messages. Be sure to get the code on the upper left of the wall. 

Step 2: Behind one of the bookshelves by the crates, there is a glowing door. Get close to it with your character to advance to the mini-quest. Note: This will teleport you to another external map. It is also single player.

Step 3: Once you spawn in this new map, walk down the path until you reach a door. Input the code you found on the wall in Lucid's realm in the chat. If you successfully type it in the chat, the door should open and you will be able to advance. Upon advancing, you will fall into a pitch black void. Simply move your way around until you find the hidden opening.

Step 4: Once you find the hidden opening in the pit, you will enter a maze. Within the maze, there are several spheres of different colors with different numbers. Keep these numbers and colors in mind as they will be needed in a bit. There are a total of six spheres within the maze.

Step 5: When you have found all the spheres and taken notice of the colors and numbers on them, head into the glowing door in the maze to advance to the next part.

Step 6: You'll be teleported to the other side of where you originally fell. Simply head towards the white wall that leads to a secret opening and walk through it. Be careful when you arrive to the white wall as it leads to another area.

Step 7: You should then reach a platform with a color puzzle ahead of you. You need to jump on the correct color for each platform that corresponded with the spheres you found in the maze. The order you follow should be from 1 to 6. So, whatever color was the '1' sphere, you jump on that color for the first platform and whatever color was the '2' sphere, you jump on that color on the next platform, and so on. If you forgot the colors and numbers on the spheres, the red glowing sphere at the beginning of the platform will take you back to re-check the maze. If you jump on the incorrect color platform, you will also be taken back to the maze.

Step 8: Upon completing the puzzle, head through the wall and you will be in a strange grid-like area. Continue moving forward until you reach the end. You should hear a sound effect when you reach the end.

Step 9: You'll enter the final area and be at the center of none other than the Council of the dream world! Move forward and interact with Lucid who is before the Council. The dialog will depict what happened on the day that Lucid got sentenced. At this point, you should have recieved the 'eternal slumber' when stepping on the circle where Lucid is. Congratulations! You made it this far!

Step 10: After this, you're practically done! If you wish to return to the main game, there is a glowing door to the left of the room. Touch it and you'll be teleported back to the main game.