For the Game Master
The rest of the Mystical Dungeon manual is for the game master. If you are not the game master, do not read any further. If you are the game master, be sure to read the For the Players section first to familize yourself with the situation. Read that section to the players to get started. Then ask the players what they want to do.
If the children, the door, and the sign freak the characters out and they decide to move on, like the children, then they will have a wonderful time on Halloween, but this adventure would be over. It's possible to salvage the situation, read the Side Quest: Save the Children below. On the other hand, if they decide to enter the door way, then the real adventure starts (skip to Enter the Dungeon section below.)
Side Quest: Save the Children
To motivate the characters to enter the dungeon, introduce a weeping mother on the side of the street. When the characters inquires the about the trouble, the mother will explain that her children entered the "Mystical Dungeon" shop, but has not returned. She has been unable to open the door and enter the shop herself to retrieve her children.
Hopefully at this point, the characters will be compassionate enough to volunteer to help her retrieve her children. If they do not have the compassionate heart right off the bat, she will plead and beg her. They may enter the shop themselves or accompany her.
Perhaps, the sheriff happens upon the situation. But he's too busy keeping the town in order on Halloween night, so he deputizes the party to retrieve the children.
Enter the Dungeon
After the characters enter the doorway, read the following to the players.
The room is about thirty feet by twenty feet. Torch light dimly lit the room from all four walls. The walls, ceiling, and the floor are made out of stone. It looks more like a dungeon then the inside of a shop. There are corridors leading out at each of the other three walls. The wall behind you has the door that you just came through. But when you look back at the door, it vanishes right before your eyes, leaving a solid stone wall behind you.
If the characters are unarmed upon entering the dungeon, help them get armed using the next section. Otherwise, move on to the "Random Dungeon" section.
Weapons and Ammunition
If the players are out unarmed during the Halloween night, then there are a few tables with weapons, armors, and other items on them. These items gives the players a chance to arm themselves before entering the dungeon depth. Let the players select their equipment from the Cyno's Fantasy supplement equipment lists. If they come fully-equipped, then you might consider skipping this part to save time.
If the players look carefully around the room, they'll see that there are pebbles on the floors of the dungeon. These pebbles can be used as ammunitions for the sling shot. In each dungeon room, if they spend the time to look for pebbles, they will find 1D6 pebbles on the dungeon floor.