From the introduction:
With pencil and paper, draw a map of the most important of the houses you lived in while a child. Important, as in, important to you. Note each room, the doors, stairs, windows perhaps. Every part of the house that was important to you, that you let your mind go into, can be considered a room.
Now in each room, write the name of or illustrate a difficulty that you will seek to overcome in the next phase of play. The difficulties can be related to your young life, or your present life, or not related to either. They could be weighty conversations, or physical barriers, or distractions, or metaphors. Make sure each room has a difficulty.