Head through the heavy door and drop down and run right, taking the upper ledge, to reach a set of three levers. Activate all three and then use the Twins special ability to hold the lever while they enter the gate and head for the house.
Run right and jump up the lower of the two ledges to meet Daddy and grab the Umbrella. Head to the top of the maze-like mansion and use the umbrella on the Attic Hatch and get the Cave Painting inside.
Now, head all the way downstairs to the kitchen and meet Mummy and grab the Hammer from the toolbox nearby. Return to the attic and use the hammer on the Loose Floorboard and then head right.
Grab the Fuse from the Fuse Box and then push the nearby box all the way down to the kitchen, stopping in the room just below the attic to place the fuse in the Empty Fuse Box, and push the box in front of the old fashion elevator.
Now, pull the Dumbwaiter Switch and head back to the room where you placed the fuse and push the box to the window.
Return to the kitchen and this time use the Twin's special ability to pull the switch and stand take the elevator yourself. Here you will find an Empty Chamber Pot and a trophy/achievement for jumping on the bed til it breaks. Once again, return to the kitchen and then climb the ladder to reach the bathroom above and use the chamber pot to get water from the Faucet.
Head to the room where you left the box and use it to jump out the window and climb the ropes to the roof. Using the filled chamber pot, dump the water down the Chimney and then climb down to get the Skeleton Key.
Open the Study Door and head to the Living Room Door just below it and knock over the bookshelf for another Cave Painting. Now head all the way down and unlock the Cellar Door and grab the Dog Food to place in the Empty Dog Bowl upstairs.
Time to switch to another party member, and head left and then across to a Pile of Bones to grab a Femur. Continue your downward descent, getting a Cave Painting and head through the dog house to reach the area under the house and turn the Steam Valve.
The Twins can now grab the Rat Poison from the cellar.
Place the twins by the Pot of Soup and then taunt the Guard Dog with the femur to distract Mummy. While she isn't looking, pour the posion into the soup and then use the faucet upstairs. You can now use the Skeleton Key to exit the door that Daddy was blocking.
