Start: Talk to the boy near the gate entrance of Taverley.
Requirements: You must be able to defeat 4 monsters from level 19 to 53 without a break or stopping to eat food. This should not be hard for any player over level 60. A player with a combat level of 39 can do this quest easily with level 37 prayer for Paralyze Monster.
Back up the ladder, go through the door opposite the front door. Drop the cheese and the rat will come out. Attach the magnet to it. Be quick before the rat leaves! The rat should open the door as read in the diary.
Go through the back door and try to open the shed door.
You will hear foot steps. Head to the house door next to the door you entered the garden through and hide in the small room. Nora T Hag will come out and open the shed. If she catches you, she'll teleport you to the Crafting Guild, and you'll have to go back and grab the magnet again and cheese.
Once she's gone back into the house, you can try to get the ball. Go into the shed and attack shapeshifter. Kill it in all four forms, then pick up the ball and take it back to the boy. NOTE:If you flee from the battle, must restart the fight from the beginning.